KIT-8D
MULTITESTER
KIT-8D
Assembling Training for
Circuit tester
Instruction Manual for Assembling and Operation Procedures
Contents
I Instruction Manual
1-1 Safety Precaution – read before use
1-2 Product Description
1 Application and Features
2 Names of Various Parts
1-3 Explanation of Functions
1 Description of Each Function
1-4 Measuring procedure
1 Pre-operation Check
2 Preparations for measurement
3 Measurement of DC Voltage (DCV )
4 Measurement of AC Voltage (ACV ~)
5 Measurement of DC Current (DCA )
6 Measurement of Resistance (Ω)
7 Battery Check (1.5V)
8 Other Measurements
1-5 Maintenance
1 Service Check
2 Calibration
3 Replacing the fuse and batteries
4 Storage
1-6 Troubleshooting
1-7 Repair Parts
1-8 Specifications
1 General Specifications
2 Working Range and Tolerance
1
2
2
2
3
3
4
4
4
5
6
7
8
9
10
12
12
13
13
14
15
15
16
16
16
II Basic Knowledge on Testers (Circuit Testers)
2-1 What is a tester?
17
17
2-2 Principle of a Meter
2-3 Structure of a Tester
18
2-4 Ohm’s Law
20
20
2-5 Calculation of Effective Resistance
2-6
2-7
2-8
2-9
2-10
2-11
SI Prefix
Multiplier
Shunt
Rectification Circuit
Principle of an Ohm Meter
Color Code and Rating Code
21
21
22
23
24
25
III
3-1
3-2
3-3
3-4
3-5
Tester Assembly
Properties of Soldering
Soldering Method
Soldering Practice
Preparations for Assembling
Assembling and Wiring
26
26
27
27
28
IV
4-1
4-2
4-3
4-4
Operation Test and Calibration
Quick Operation Check
Calibration of the Tester
Measurement Results
Summary of the Results
43
45
46
47
V Circuit Calculation of the Tester
5-1 Meter Circuit
5-2 DCA Circuit
5-3 DCV Circuit
5-4 ACV Circuit
5-5 Ohm Meter (Ω) Circuit
5-6 Battery Check Circuit (1.5V)
- KIT-8D Type Circuit Diagram
48
49
49
51
52
54
55
VI Assembly of Buzzer Kit
(Optional Accessory)
- Parts List Sheet
56
61
I Instruction Manual
1-1 Safety Precaution – read before use
Thank you for buying Sanwa Tester Kit <KIT- 8D>.
The contents of ‘For Safe Use’, ‘Measurement’, and ‘Maintenance’ described in these operating
instructions are particularly important. Read these items well before use for safe and correct
operation. Keep these operating instructions with the product.
Use of the product without reading the operating instructions may result in personal injury
including burn and electric shock and destruction of the product. Read this manual before use.
Description of symbols such as Warning
Certainly follow the ‘Warning’ and ‘Caution’ items described in the text. Improper method of
use may cause personal injury including burn and electric shock and damage of the product.
Meaning of the symbols used on the product and in these ‘Operating Instructions’
(Warning symbol)
(High voltage symbol)
(Fuse symbol)
(DC symbol)
(AC symbol)
This indicates items especially important for safe use. Read the
description well. The ‘Warning’ describes items to be followed
to avoid personal injury while the ‘Caution’ describes items on
handling that may damage the product. Be sure to follow the
instruction.
Be careful of the impressed high voltage.
Fuse
Direct current (DC)
Alternating current (AC)
For Safe Use
The items described below are warnings to prevent personal injury such as burns, electric
shock, etc.
Be sure to follow the instructions when using the product.
Warning
1. Do not use the device to measure power lines not less than 6kVA.
2. Danger of electric shock if the voltage being examined is not less than DC70V or
AC33Vrms, 46.7Vpeak.
3. Do not use the device when your hand or the device itself is in wet conditions.
4. Be sure to carry out ‘range check’ for each measurement.
5. Do not use the device in conditions where the rear case is open or the rear case and
its insulating parts are damaged.
6. Do not alternate or disassemble the device except for operations instructed in this
manual.
7. Always use the same rating internal fuses.
8. Use test leads of the specified type.
1
9. Do not use the test leads when the envelope is damaged ; replace the leads with new
ones.
10. Do not hold the test leads over the brim at the test pin end when measuring.
11. Be careful not to apply over-voltage when measuring pulsating waves or waveforms
including pulses.
12. Check the device at least once a year.
13. Do not switch to other ranges during measurement.
14. Do not use the product for line measurement such as motors that generate induced
voltage or voltage surges.
1-2 Product description
1 Application and features
Application… This product is a portable learning kit designed for measurement of smallcapacity electric circuits. The product is suitable for measurement of small
communication devices, household appliances, lamp line voltage and
batteries.
Features….... 1) Equipped with lightweight, small, high-sensitivity and shock resistanttype taut band meter.
2) Basic functions include measurement of DCV, ACV, DCA and Ω.
In addition, the battery check range allows inspection of 1.5V-dry
battery at an actual load (20Ω).
3) Direct-mount test leads ensure no need to worry about missing of leads.
Convenient storage space within the main body available.
4) Panel protection cover equipped ; also acts as a stand.
5) Hand strap convenient for carrying.
2 Name of various parts
Hand Strap
Test Pin
Panel
Needle Indicator
Meter Cover
Brim
Scale Plate
Spare Fuse
AA Size
Batteries
Fuse
Meter Zero
Adjuster
Printed Board
Zero Ω Adjuster Knob
Test Leads
(Red & Black)
Range
Selector
Knob
Protection Cover
Rear Case
Test Lead
Storage Space
- Example of use as a stand 2
How to read the scale plate
Measurement
Range
Ω × 1k
Ω × 10
Ω×1
DC300V
AC300V
DC0.3A
DC30V
AC30V
DC30mA
DC3V
DC3mA
DC0.3V
DC600V
AC600V
DC60μA
DC120V
AC120V
DC12V
AC12V
Internal resistance per 1V : (Example) the internal resistance of DC3V range is
3V × 20kΩ = 60kΩ
1.5V
Scale Factor
× 1k
× 10
×1
×1
×1
× 0.001
× 0.1
× 0.1
× 0.1
× 0.01
× 0.01
× 0.001
× 10
× 10
×1
× 10
× 10
×1
×1
×1
Scale to
be used
①
②
③
④
Fig 1-1
1-3 Explanation of Functions
1 Description of each function
Range selector
This is a switch knob to select measuring functions. Adjust the range selector knob to the
range to be examined.
Meter zero adjuster
This is a device to adjust the needle indicator to zero (the left end of the meter scale).
Zero Ω adjuster knob
This is a device to adjust the needle indicator to zero of the Ω scale (the right end of the
meter scale) before Ω measurement.
How to use the protection cover
-----------------Fig 1-2-----------------1 Insert the installation pin inside
1. Install the cover as illustrated in Fig a ; put the
the cover into the ditch of the
cover onto the rear case side or the panel side
main body and slide it.
2 Close the cover.
when you use or do not use the product,
respectively. Do not press the cover down
from above the main body as shown in Fig b ;
this will break the cover.
Installation Pin
2. Connect the cover as illustrated in Fig c when
(Fig a)
you use it as a stand. Do not close the cover
Ditch
while it is still connected as a stand ; this will
break the cover.
(Fig b)
3
(Fig c)
Note) Indication error may become larger if
you use the meter in a standing
position because the meter is not
placed horizontally.
(Fig d)
Protection
Cover
Storage of the test leads
Store the test leads in the storage space as illustrated in
the right figure (Fig 1-3) when you do not use the
device. How to store : make three small rings with the
lead lines, put them into the storage space and then put
the test rods into the space, the test pin side first.
Fig 1-3
1-4 Measuring procedure
1 Pre-operation check
Warning
Always inspect the main body, test leads and fuse before use.
1. Check if there is any damage in the appearance due to drop shock, etc. Do not use
the product if any damage is found.
2. There is a danger of electric shock if the cord of the test leads is damaged or the core
wire is exposed. Do not use the product in such conditions.
3. Check and ensure that the test leads or the internal fuse is not broken.
(See P. 12 ‘Maintenance’ / Internal Fuse, a-(3))
2 Preparation before measurement
1) Meter zero adjustment
Turn the zero adjuster of the meter to adjust the needle to zero at the left end of the
scale. You do not have to frequently carry out this zero adjustment operation, though
you should be careful about zero adjustment because deviation of the needle indicator
from the zero point will lead to indication errors. Zero adjustment is a basic procedure
and hence important to practice when you use measuring devices. See the figure below
for the method.
2) Turn the range selector knob to select the measurement range to be used.
Turn to adjust the
needle to the zero
scale here.
Fig 1-4
4
3 Measurement of DC voltage (DCV
)
Measurable voltage : max. DC600V
Warning
1. Never impress input signals that exceed the maximum measurable voltage of each
range.
2. Be sure to carry out ‘range check’ for each measurement.
3. Do not switch to other ranges during measurement.
4. Never carry out measurement when your hand is wet.
5. Do not hold the test leads over the brim at the test pin end when measuring.
1) Objects to be measured
Direct current voltage including general battery cells, radios, amplifiers, etc.
2) Measurement range
7 ranges : 0.3/3/12/30/120/300/600V
3) Measurement method
Connect the meter in parallel with the circuit. Be sure to connect to the correct
polarity during measurement of direct current voltage. (The needle will swing
backwards if the connection is reversed.) The illustrations below show how to do this:
(Black)
(Red)
(Dry battery)
1. Adjust the range selector
knob to the optimal range
among the DCV ranges.
2. Connect the red and black
test pins to the plus and
minus sides, respectively,
of the object being examined.
---------------------Fig
3. Read the scale deflection
by the V.A scale.
1-5----------------------
Memo
The ‘optimal range’ means the range where the needle indicator points the scale as near to
the maximum as possible (right-hand side) to achieve high accuracy of the readout. (Select
the range that is larger but also near to the value to be examined, e.g. choose 3V-range for
measurement of 2V, 12V-range for measurement of 10V, etc.)
Try the maximum range (600V) first if you cannot guess the approximate value.
5
4 Measurement of AC voltage (ACV)
Measurable voltage : max. AC600V
Warning
1. Never impress input signals that exceed the maximum measurable voltage of each
range.
2. Be sure to carry out ‘range check’ for each measurement.
3. Never carry out measurement when your hand is wet.
4. Do not switch to other ranges during measurement.
5. Do not hold the test leads over the brim at the test pin end when measuring.
1) Objects to be measured
Tap voltage of small power transformers, voltage of lamp lines, etc.
2) Measurement range
Five ranges: 12/30/120/300/600
3) Measurement method
Connect the meter in parallel with the circuit. The polarity of the power source does
not affect the readout in AC voltage measurement. The illustrations below show how to
do this:
Scale
exclusive for
AC12V
1. Adjust the range selector
knob to the optimal range
among the ACV ranges.
2. Connect the test pins to
the object being examined.
---------------------Fig
Note
6
3. Read the scale deflection
by the V.A scale. (Use the
AC12V scale for AC12V
range measurement.)
1-6----------------------
Effect of waveform : Errors occur in measurement of waveforms other than sine wave.
Effect of frequency : Errors will be larger for higher frequencies.
Use the meter within the frequency range of 30Hz - 50kHz
(AC12V range).
5 Measurement of DC current (DCA
)
Measurable current : max. DC0.3A
Warning
1. Do not impress voltage to the current measurement range. It may cause burns or
electric shock.
2. Never apply input signals to the input terminal that exceed the maximum measurable
current.
3. Always connect in series with the circuit.
4. Be sure to carry out ‘range check’ for each measurement.
5. Use the device only for low-current circuits.
6. Never carry out measurement when your hand is wet.
7. Do not switch to other ranges during measurement.
1) Objects to be measured
Electric current of circuits that include batteries, rectification circuits, etc.
2) Measurement range
4 ranges : 60μ / 3m / 30m / 0.3A
3) Measurement method
Connect the meter in series with the circuit. Be sure to connect the correct polarity
during measurement of direct current voltage. The illustrations below show how to do
this :
(Black)
(Red)
1. Adjust the range selector
knob to the optimal range
among the DCA ranges.
2. Turn off the power of the
circuit to be measured;
break the circuit. Connect
the red and black test pins
to the plus and minus
sides, respectively.
---------------------Fig
Note
3. Turn on the power of the
circuit to be measured.
Read the scale deflection
by the V.A scale.
1-7----------------------
Since the internal resistance of the current range is included in series in current
measurement, the current will be reduced by this amount. This effect will be larger
in lower-resistance circuits.
7
6 Measurement of resistance (Ω)
Measurable resistance : max. 2MΩ
Warning
1.
2.
3.
4.
5.
Never impress voltage at resistance range.
Be sure to carry out ‘range check’ for each measurement.
Circuits to which voltage is applied cannot be measured.
Never carry out measurement when your hand is wet.
Do not switch to other ranges during measurement.
1) Objects to be measured
Resistance measurement of fixed resistors, check of wiring connection and wire breakage
2) Measurement range
3 ranges : × 1 / × 10 / × 1k
3) Measurement method
See the illustrations below :
1. Adjust the range
selector knob to the
range so that the
needle indicator
points around the
center of the scale.
2. Short-circuit the
test pins together.
4. Connect the test
3. While the test pins
pins to the object
are sill short-circuited,
to be examined.
turn the zero Ω
adjuster knob to
adjust the needle to
zero of the Ω scale.
0 Ω adjustment
‘Zero Ω adjustment’ is a procedure to be carried out prior to
measurement of resistance in order to adjust the needle
indicator to the zero graduation of the Ω scale (the right end
of the scale) by turning the zero Ω adjuster knob while the
test pins are short-circuited. Carry out 0 Ω adjustment each
time you switch the range ; do it at a suitable time for
continuous measurement.
The
needle indicator may not reach the 0 Ω graduation when
5. Read the scale
you turn the zero Ω adjuster knob to fully right during zero Ω
deflection by the
adjustment. This suggests that the internal batteries are
Ω scale.
------Fig 1-8----consumed. Replace the internal batteries.
Polarity of the tester during resistance measurement
For resistance range, as seen in the circuit diagram, the red test
lead becomes minus while the black test lead becomes plus.
Errors occur because of the effect of the resistance of human body if you perform measurement
with your finger touching to the test pins (especially for ×1k range).
Resistance of fuse
Zero Ω adjustment may be impossible at ×1 range or measurement accuracy may be reduced
because of fuse resistance when you use a fuse lower than the rating (0.5A) or a fuse filled
with arc-extinguishing medium.
Always use a fuse of the same rating and specifications.
Memo
8
7 Battery check (1.5V)
Load resistance RL = 20Ω
Warning
1. Be sure to carry out ‘range check’ for each measurement.
2. Do not switch to other ranges during measurement.
1) Objects to be measured
Manganese dry batteries (SUM-1 / R20, SUM-2 / R14, SUM-3 / R6), alkaline batteries
(LR20, LR14, LR6), etc.
2) Measurement range
One range : 1.5V / RL = 20Ω
3) Measurement method
Voltage is measured by connecting the load resistance to the battery to draw the current
of that instant. This allows examination at nearly the same conditions as in use. See the
illustrations below for the measuring procedure :
(Black)
(Red)
1. Adjust the range selector
knob to the battery check
range.
2. Connect the red and black
3. Read the scale deflection
test pins to the plus and
by the battery check scale.
minus sides, respectively,
of the object being examined.
---------------------Fig
Note
1-9----------------------
Do not measure voltage of button cell batteries that have small current capacities ;
the load is too much for these.
A voltage value of 0.9 to 1.6V can be judged as good for batteries in general. Note
that the value judged as good varies in accordance with the device the batteries are
used for.
9
8 Other measurements
An easy way of checking electronic components using the Ω range is introduced here. You can
also check operation of each electronic component. See the following description for reference:
a) Check of a diode
The following procedures enable judgement of quality of a diode.
For non-defective diodes, the meter will show a large deflection in
the forward direction while deflection in the reverse direction will
be negligible. For reference, the figures here show each condition
when you check a diode.
Cathode mark
K
A
Graphic symbol
How to check
Adjust the measurement range to ×10
or ×1k and then carry out zero Ω
adjustment. Connect the test pins as
shown in the figures and read the
deflection of the needle indicator to
judge if the diode is good or defective.
(Black)
(Black)
(Red)
(Red)
Measurement of
forward direction
Measurement of
reverse direction
Judgement
Deflection of the needle indicator for forward direction
Deflection of the needle indicator for reverse direction
Non-defective
Short-circuit
the position of the
needle is as in the
figure for both
forward and reverse
directions
The position of the needle :
left side : ∞ direction ;
right side: 0 Ω direction
Wire breakage
the position of the
needle is as in the
figure for both
forward and reverse
directions
Deteriorated
b) Check of a light emitting diode (LED)
The procedures described in a) for check of a diode can also be applied
to the check of an LED.
The measurement range for light emission by an LED is somewhat different.
Graphic
symbol
How to check
Adjust the measurement range to ×1
or ×10 and then carry out zero Ω
adjustment. Connect the test pins as
shown in the figures and read the
deflection of the needle indicator to
judge if the LED is good or defective.
Note) Check the capacity of LED for
measurement at ×1 to prevent overcurrent.
10
Measurement of
reverse direction
Measurement of
forward direction
(Black)
(Black)
(Red)
(Red)
Judgement
Deflection of the needle indicator for forward direction
Deflection of the needle indicator for reverse direction
Non-defective
light will be emitted
at forward direction
Short-circuit
light will not be emitted
in either forward or
reverse directions
The position of the needle :
left side : ∞ direction ;
right side : 0 Ω direction
Wire breakage
light will not be emitted
in either both forward or
reverse directions
c) Check of a transistor
The Ω range offers an easy way also for judgement
of the quality of a transistor.
See the following description for the method of
judgement.
NPN
type
PNP
type
Graphic symbol
How to check
Adjust the measurement range to ×1k and then carry out zero Ω adjustment. Connect the test
pins to the transistor being examined as shown in the figures.
- Check between B and C -
(Red)
(Black)
- Check between B and E -
(Red)
(Black)
Judgement
For NPN transistors :
The transistor is in good condition if the needle indicator is deflective during measurement in
the direction shown in the solid lines while it does not move during measurement in the
direction shown in the broken lines (for both of B-C and B-E check procedures).
For PNP transistors :
The transistor is in good condition if the needle indicator is deflective during measurement in
the direction shown in the broken lines while it does not move during measurement in the
direction shown in the solid lines (for both of B-C and B-E check procedures).
11
d) Check of a capacitor
The meter also offers a way to check relatively
large-capacity capacitors such as electrolytic
capacitors.
When the test pins are connected, the needle
indicator will move because of the charging
current of the capacitor and then return gradually
to the origin. The needle indicator will twitch only
slightly for an instant when you check a smallcapacity capacitor since the charging current of the
capacitor is small.
Check of a capacitor should be performed after
discharging it. (Short-circuit the terminal of the
capacitor.)
Polar
capacitor
Non-polar
capacitor
How to check
Connect the test pins to both the electrodes of the
capacitor. (Connect the black test pin to the plus side
and the red test pin to the minus side of the
capacitor.) Use the measurement range that allows
the needle indicator to swing far to the right side. The
capacitor is normal if the needle indicator moves
once and then comes back near to the ∞.
(Red)
(Black)
1-5 Maintenance
Warning
Do not open the rear case unnecessarily, except for the operations needed for
maintenance described in the instruction manual.
1 Service check
Warning
1. Appearance : Check if there is any damage in the appearance due to drop shock, etc.
Do not use the meter if any damage is found.
2. Test leads : There is a danger of electric shock if the cord of the test leads is damaged
or the core wire is exposed. Do not use the meter in such conditions.
3. Internal fuse : Check and ensure that the internal fuse is not blown out. See below for
checking procedures.
Procedures to check the internal fuse
1 Adjust the range selector knob to ×1k of the Ω range.
2 Short-circuit the test pins.
3 The fuse is normal if the needle moves ; the fuse may be blown out if the meter does not
respond. Replace the fuse with the spare fuse included in the main body and repeat the
procedures once more.
12
2 Calibration
Warning
Check and calibrate the product at least once a year for safety and maintenance of
accuracy. Inquire with the distributors or the selling agencies to request check up and
calibration.
3 Replacing the fuse and batteries
Warning
1. Do not remove the rear case except when you replace the fuse or the internal batteries
in accordance with the procedures described in this manual.
2. Always make sure before following the procedures that the test pins are not
connected to the circuit to be measured.
3. Use a fuse of the same rating for replacement.
Never use a fuse of other ratings. Never short-circuit the fuse holder terminals with
copper wire or other materials.
1)
Replacement of the batteries
When the internal batteries are consumed, you cannot adjust the needle indicator to zero in
zero Ω adjustment procedure even if you turn the zero Ω adjuster knob fully to the right at
Ω range. If you find out that zero Ω adjustment is impossible, replace the internal batteries.
How to replace the batteries
1 Remove the protection cover installed
on the main body.
2 Unscrew the case stopper screw and
remove the rear case.
3 Take out the consumed batteries and
replace them with new ones. Be sure
to put the batteries stably into the
battery holder in correct polarity
(+ and -).
4 Put the rear case onto the panel and
screw the case stopper screw.
5 Put the protection cover back onto the
main body.
Note
Use the batteries specified for the
product
(Two AA dry batteries UM-3/R6)
Insert batteries in accordance
with the direction (polarity)
indicated on the panel.
Spare Fuse
Dry Batteries
(two batteries)
Fuse
13
2) Replacement of the fuse
Warning
Use a fuse of the same rating for safety and maintenance of performance.
(Place an order to our company if it is difficult to obtain.)
The rating of the fuse used
0.5A / 250V (5.2 mm in diameter, 20 mm length, in a glass tube ; rupturing capacity : 300A)
If you impress lamp line voltage (100V) etc. to Ω, DCA, or battery check range by mistake, the
fuse will blow out to protect the circuit.
The main cause that the needle indicator never twitches during the procedures to make the
needle move at Ω range is a blown-out fuse.
How to replace the fuse
1
2
3
4
5
6
Remove the protection cover installed on the main body.
Unscrew the case stopper screw and remove the rear case.
Remove the blown-out fuse from the fuse holder ; replace it with a new one.
Put the rear case onto the panel and screw the case stopper screw.
Check if the indication of each range is normal.
Put the protection cover back onto the main body.
Use the spare fuse included in the main body.
4 Storage
Caution
1. The meter cover is treated with antistatic treatment. Do not rub hard with a cloth or
other materials. In the case that charge is built up after many years of use, temporary
measures may be effective : apply neutral detergent diluted several times with water
onto the surface of the cover.
2. Avoid vibration such as loading on a motorbike ; the meter may fail to operate.
3. Do not leave the device for a long time under direct sunlight, at high temperature
(> = 60°C), high humidity (> = 85%) or under the conditions in which dew will
condensate.
4. Do not use thinners or alcohols for cleaning of the device. Wipe the dust off lightly
with a soft brush or a cloth.
14
1-6 Troubleshooting
Check the following items before sending out for repair :
Status
No indication for all the ranges
(The indicator does not move
at all)
Indication for Ω range not
available
Zero Ω adjustment impossible
Checkpoint
Treatment
Has the fuse been blown out ? Replace the fuse.
Has the test lead been broken? Make a request of repair to
our company.
Has the internal batteries been Replace the internal
consumed?
batteries.
1-7 Repair parts
Replacement fuse (0.5A / 250V, 5.2 mm in diameter, 20 mm length, in a glass tube ;
rupturing capacity : 300A)
Place an order to the Service Section of our company for replacement fuses : specify the
model of the product and the name of the parts and send postage stamps for the amount of
the price of the parts and the mailing cost.
Price of a fuse : ¥ 42 (consumption tax inclusive)
Mailing cost : ¥ 120 for not more than 10 fuses
[Address] Service Section, Sanwa Electric Instrument Co., Ltd.
4-7-15 Shinmeidai, Hamura-shi, Tokyo 205-0023
TEL (042) 554-0113 FAX (042) 555-9046
Inquiries
Make inquiries to our company for questions about the product :
Tokyo Headquarter : TEL (03) 3253-4871 FAX (03) 3251-7022
Osaka Sales Office : TEL (06) 6631-7361 FAX (06) 6644-3249
E-mail
: infotokyo@sanwa-meter.co.jp
Web site of Sanwa Electric Instrument Co., Ltd. : http://www.sanwa-meter.co.jp
15
1-8 Specifications
1 General Specifications
Circuit Protection
Frequency Characteristics
Internal Batteries
Internal Fuse
Accessories
Optional Accessories
Size & weight
Protection by the fuse and the diode is available against
impression of voltage not exceeding the commercial power
supply, AC200V, to all the range for a duration of 5 seconds.
(Repeated impression may deteriorate the diode.)
30 - 50kHz (AC12V range)
Two AA size manganese dry batteries UM-3(1.5V)
Two fuses (one for spare) ; 0.5A / 250V, 5.2 mm in diameter,
20 mm length, in a glass tube ; rupturing capacity : 300A
One copy of operating instruction manual
Buzzer kit
159.5 × 129 × 41.5 mm, ca. 320 g
2 Working range and tolerance
Measurement function
DC voltage (DCV)
AC voltage (ACV)
DC current (DCA)
Resistance (Ω)
Battery check
Measurable range
0.3V (internal resistance : 16.7k Ω / V)
3 / 12V (internal resistance : 20k Ω / V)
30 / 120 / 300 / 600V (internal resistance : 9k Ω / V)
12 / 30 / 120 / 300 / 600V
(internal resistance : 9k Ω / V)
60μ / 3m / 30m / 0.3A
voltage drop across the terminals : 0.3V
(Note) : fuse resistance not included
(5k Ω / 100.5 Ω / 10.5 Ω / 1.5 Ω) (internal resistance)
(Note) : fuse resistance included
×1 / ×10 / ×1k
(20 Ω / 200 Ω / 20k Ω)
(graduation at the middle of the scale)
D, C, AA, and AAA size batteries
(load resistance : 20 Ω)
Note) Tolerance warranty conditions :
Temperature : 23 ± 2°C
Humidity : 45 - 75%
Posture : horizontal (± 5°)
Sine wave for AC range (50Hz or 60Hz)
16
Tolerance
Within ± 3% of the
maximum scale
Within ± 4% of the
maximum scale
Within ± 3% of the
maximum scale
Within ± 3% of the
scale length
-------
II Basic knowledge on testers (Circuit testers)
2-1 What is a tester?
A tester (circuit tester), as the name suggests, is a measuring instrument designed to be very
convenient for the check of circuits. The device has a structure that enables vast varieties of
measurement including voltage, electric current and resistance by change of connection of the
test leads or switching of the rotary switch, though it is not suitable for precise measurement in
view of circuitry. In simple terms, it is like a stethoscope that physicians use. The point of
difference from a stethoscope is that a tester clearly expresses in the form of a numerical value
the electricity that cannot be usually seen. Since there is no need for precise measurement in
testing of general electric circuits except for special cases, a tester is good enough for circuit
check even though it has relatively large indication errors (tolerance).
2-2 Principle of a meter
A meter is a device that converts an electrical quantity (voltage, current and resistance) into a
mechanical quantity. A simple explanation is made here using Fig 2-2 : When an electric current
is applied to the coil placed in the magnetic field of the permanent magnet NS, the coil will
rotate in the direction shown by F and F’ according to Fleming’s left-hand rule illustrated in Fig
2-3. The control spring will work so that it swings at an angle in direct proportion to the electric
current and hence the quantity of the current applied will be indicated in a scale of linear
rotation angle. Meters that use the principle described above are called moving-coil meters.
This principle suggests that strength of the permanent magnet, number of turns of the coil and
strength of the control spring are important elements for a meter.
There are different methods to support the moving coil : Fig 2-1 (a) illustrates the pivot
suspension that uses a pivot and a jewel, while (b) designates the taut band suspension system
that uses a taut band to support the coil. The moving-coil meters are classified into two
categories according to the position of the permanent magnet : external or internal. An external
magnet meter has a permanent magnet outside of the moving coil, while an internal magnet
meter has it inside. Internal magnet meters have high magnetic efficiency and, since they do not
require any pole piece, they can be constructed small and lightweight ; operation of the close
ring prevents magnetic field interference. External magnet meters can adopt large magnets and
are suitable for high-sensitivity models.
Zero adjuster
Control Spring
Indicator
Balancing Weight
Fram
Moving Coil
(Iron Ball)
Boss
Control Spring
Operation principle of a moving-coil meter
Meter Terminal
Pivot
Meter Terminal
Boss Stopper
Boss
Fig 2-2
F (Force)
H (Magnetic Field)
Jewel
Coil Spring
(a) Pivot suspension system
Fig 2-1
Taut band
Tension spring
(b) Taut band suspension system
Meter Structure
I (Electric Current)
Fleming’s left-hand rule
Fig 2-3
17
2-3 Structure of a tester
A tester consists basically of the meter unit that indicates the electric charge, the resistor unit
that magnifies the scale, the rectifier unit (diodes) that converts alternating current into direct
current, and the battery unit that supplies power for measurement of resistance.
Circuit components such as diodes and fuses are combined in addition to the units described
above as protection circuits in view of safety.
1 Rectifier (Diode)
The direction of the alternating current is reversed
periodically. Since the deflection of the two
opposite directions cancel each other, a movingPolarity mark
coil meter will hardly operate. A rectifier has the
(Symbol)
(Cathode mark)
role to convert the alternating current into direct
current by passing only one direction of the
Forward Direction
alternating current.
(Low resistance)
Silicone diodes are usually used for rectifiers
Reverse Direction
because of favorable frequency characteristics and
(High resistance)
reverse breakdown voltage. An exclusive set of
Fig 2-4
scale marks is devised for the AC12V range in this
product.
The reason for this is that, because the resistance of the multiplier is low at a low voltage range,
the resistance change of the rectifier that is connected in serial with the multiplier (which
changes in accordance with the amount of the electric current) will be greatly affected.
The indication is not affected at higher voltage range because the resistance of the multiplier is
large and hence the change can be neglected.
2 Battery (Manganese dry cell)
The batteries used in a tester will operate as an
electric power supply required for resistance
measurement.
A small tester usually uses one or two UM-3 type
(1.5V) dry cells (1.5V - 3V). Since the higher
voltage of the batteries enables measurement of
higher resistance, some high-class testers adopt
S-006P (9V) layer-built dry cells.
The voltage of a new battery is usually about
1.65V, higher by around 10% compared to the
value indicated (1.5V). Also, a new layer-built dry
cell usually has a higher voltage, about 10V,
compared to the indicated value, 9V.
3 Resistor
Metal film resistors are widely used in testers
because of good accuracy and temperature
characteristics.
The recent trend of miniaturization and
densification has introduced many chip resistors
that have no lead wires. The components of testers
have become more of the chip-type in recent years.
Pole
Pole
(Symbol)
Fig 2-5
Cap
Insulation Coat
Lead Wire
Insulator
Ditch by cutting
(Symbol)
Fig 2-6
18
Metal Film
4 Zero Ω adjuster
A carbon variable resistor is used for the zero Ω
adjuster. The variable resistor of a tester has a role
to minimize measurement errors by compensating
the voltage change (wear and tear) of the internal
batteries with a circuit.
(Symbol)
5 Capacitor
Fig 2-7
Capacitors used in testers have the property that
they pass alternating current while they do not
pass direct current and are used frequently in cases
where low frequency output is measured. The
capacitor in the protection circuit of this product is
incorporated as a by-pass capacitor to prevent the
effect of high frequency.
Other than this, capacitors also have the property
to accumulate electricity and are widely used in
electric circuits as well as resistors.
Silicon diodes have the property that they start to
conduct electric current at 0.5 - 0.6V and higher
voltage at room temperature as shown in Fig 2-9.
This property is used for protection of the meter.
In normal measurement, the electric current will
not go through the diode. (Electric current passing
through the diode will be the source of
inaccuracy.) When the current is overloaded, the
voltage between the terminals of the meter will
rise and the diode in parallel with these will
conduct the electricity. Most of the electric current
will pass through the diode and the meter will thus
be protected from damage.
Fig 2-8
Electric current of forward direction
6 Meter protection diode
(Symbol)
Voltage of forward direction (V)
Fig 2-9
7 Printed board
There are several kinds of printed boards : bakelite
boards, paper epoxy boards, glass epoxy boards,
etc. Bakelite boards of 1.6 mm thickness are
generally used for testers. (Glass epoxy boards are
widely used for digital multimeters.)
In the case of testers, they have considerable
effect on simplification of the circuit wiring
because they also have the function of switch
contact. There are, however, problems such as
dielectric strength and leak current. This product is
designed considering safety ; the board is coated
with solder resist (green coating) and is split where
needed. Nevertheless, you should still take care
not to touch the printed side of the board with a
dirty hand to prevent leakage.
Fig 2-10
19
2-4 Ohm’s law
An understanding of Ohm’s law and calculation of effective resistance will provide understanding
of the circuit of a tester to some extent. Three equations shown below express the relationship
between electric quantities, i.e. voltage E [V], current I [A], and resistance R [Ω] :
E
R
E
R =
I
E =I•R
I =
………. (1)
………. (2)
I : Current
[A]
E : Voltage
[V]
R : Resistance [Ω]
………. (3)
[Example 1] How much current will flow when the SW
is turned on in Fig 2-11?
Fig 2-11
(Answer) From the Ohm’s law,
E
[A] ;
R
E = 1.5V, R=10 Ω ; and hence
E 1.5V
I= =
= 0.15 [A]
R 10Ω
I=
Fig 2-12
2-5 Calculation of effective resistance
(a) Serial Connection
R = r1 + r2 + ……. rn
……… (4)
(b) Parallel Connection
1 1 1
1
= + + .........
R r1 r2
rn
∴R =
1
……… (5)
1 1
1
+ + .........
r1 r2
rn
Fig 2-13
A generally used model, connection of two resistors, is expressed as below by transforming
R=
1
1 1
+
r1 r2
R=
r1 × r2
r1 + r2
……… (6)
or r1 =
r2 × R
r2 − R
……… (7)
[Example 2]
How much is the effective resistance of the right figure (Fig 2-14)?
r1 = 10 Ω, r2 = 20 Ω, r3 = 30 Ω
(Answer) r2 and r3 are connected in parallel ; these are connected to r1 in serial. From (4) and (6),
r ×r
20Ω × 30Ω
R = r1 + 2 3 = 10Ω +
= 10Ω + 12Ω = 22[Ω ]
r2 + r3
20Ω + 30Ω
20
Fig 2-14
2-6 SI prefix
Prefixes are used in the indication and calculation of electric quantities such as voltage [V]
when it is not easy to handle numbers too large or too small. It is important to adopt the same
unit when calculating.
Use of exponential expressions (e.g. 4.1 × 103) is also required.
Prefix
M
k
m
n
p
μ
Reading
megakilomillimicronanopicoMultiple
106
103
10-3
10-6
10-9
10-12
Example
200nF
1000pF
25mA
1.8M Ω
4.1k Ω
50μ A
=
=
=
=
=
=
0.025A
0.05mA
0.2
μ
F
0.001
μF
1800k Ω
4100 Ω
[Example 3] How much is 200μ A in amperes ? How much in milliamperes ?
(Answer)
From the table, ‘μ’ means 10-6. And hence
200μ A = 200 × 10-6 [A] = 2 × 102 × 10-6 [A] = 2 × 10-4 [A] = 0.0002 [A].
‘μ’ means 10-6 while mA means 10-3; the difference is 10-3. And hence
200μ A = 200 × 10-3 [mA] = 2 × 102 × 10-3 [mA] = 2 × 10-1 [mA] = 0.2 [mA].
[Example 4] How much voltage [V] does the battery E
have in the circuit shown in Fig 2-15 ?
(Answer)
The effective resistance R is :
R = 5kΩ +
20kΩ × 20kΩ
= 15kΩ
20kΩ + 20kΩ
Fig 2-15
From Ohm’s law,
E = I R = 600 × 10-6A × 15 × 103Ω = 6 × 102 × 10-6 × 15 × 103V = 90 × 10-1V = 9 [V]
Calculate by using the same unit for [A] and [Ω].
2-7 Multiplier
E : voltmeter before multiplying [V]
E0 : voltmeter after multiplying
[V]
R : resistance of the multiplier
[Ω]
r : internal resistance of the meter [Ω]
(resistance of the coil)
I : current sensitivity of the meter [A]
Fig 2 -16
In Fig 2-16, for the circuit between b and c, the next expression is true from Ohm’s law (1) :
E
……………… (8)
r
E 0 = I • (R + r ) …... (9)
E
E 0 = • (R + r ) … (10)
r
I=
For the circuit between a and c, from the Ohm’s (3),
Substitution of (8) into (9) gives
21
R = (E 0 − E ) •
Transformation of (10) gives
From (10),
r
(E 0 − E ) • Ω V ..…... (11)
E
⎛E
⎞
R = r • ⎜ 0 − 1⎟ …… (12)
⎝ E
⎠
We can obtain the following equation by defining that
E0
= n (where “n” is the magnification factor) :
E
R = r • (n − 1) …….. (13)
[Example 5] How much resistance is needed for R to obtain
a 10V - voltmeter from a meter of 500μ A-500 Ω as shown in
Fig 2-17 ?
(Answer) Substituting into (13) gives
E0
10V
=
= 40
E
500 × 10 −6 A × 500Ω
n=
(
)
Fig 2 - 17
R = r • (n − 1) = 500Ω × (40 − 1) = 19500[Ω] = 19.5kΩ
2-8 Shunt
The current I in Fig 2-18 is expressed as follows from Ohm’s
law (1) : I = E
r
………………… (14)
Transformation gives : E = I r
From Ohm’s law (1) and the equation for resistors in parallel
connection (5), I0 is expressed as follows :
I0 =
E
1
⎛1 1 ⎞
= E • ⎜ + ⎟ ………………… (15)
⎝r R⎠
1 1
+
r R
By substituting (14) into (15), we obtain :
r⎞
⎛
⎛1 1 ⎞
I 0 = I • r • ⎜ + ⎟ = I • ⎜1 + ⎟ ……… . (16)
⎝ R⎠
⎝r R⎠
r
…… (17)
Transformation of (16) gives : R =
⎛ I0 ⎞
⎜ ⎟ −1
⎝ I ⎠
I
r
By defining that 0 = n ,
……..… (18)
R=
n −1
I
Fig 2-18
I : Voltmeter before multiplying
I0: Voltmeter after multiplying
R: Resistance of the electric shunt
r : Internal resistance of the meter
(resistance of the coil)
E: Voltage for applying electric current
[A]
[A]
[Ω]
[Ω]
[V]
[Example 6] How much resistance is needed for R to obtain a 500 mA - ammeter from a meter of
500μ A-500 Ω as shown in Fig 2-19 ?
(Answer) Substituting into (18) gives
n=
22
I 0 500 ×10 -3 A
=
= 1000
I 500 × 10 -6 A
R = r = 500Ω ≅ 0.5 [Ω]
n − 1 1000 − 1
Fig 2-19
2-9 Rectification circuit
Testers have a structure that allows them to measure alternating current as well as direct current.
Here is a simple explanation of rectification circuit that converts alternating current into direct
current.
(a) Half - wave rectification
Fig 2-20
(b) Full - wave rectification
There are broadly two kinds of rectification circuits as illustrated in Fig 2-20. Generally,
the half - wave rectification scheme shown in
(a) is adopted in most testers. Since meters
Time Average = 0
indicate the average value of the measured
voltage, if the alternating current shown in Fig
2-21 (a) is applied to a meter, the meter will
(a) [Alternating Current]
show almost no response at 20 - 30Hz or higher
frequencies. By rectifying the current with a
rectifier (a set of diodes), the current will be
Average = Iav
converted into the waves shown in Fig (b) ; the
average value will be Iav and the meter will
(b) [Half - wave rectified current]
respond to the current. The value Iav is almost
Fig 2-21
proportional to the input voltage and
alternating currents can thus be measured.
It is generally convenient to express the alternating current by the root mean square (RMS)
value rather than the average value. The RMS value is hence used as the scale of the tester. The
following equations relate the maximum and RMS values of a sinusoidal alternating current :
average value =
RMS value =
RMS value =
2 • (maximum value)
π
(maximum value)
2
π • (maximum value)
average value =
2 2
2 2 • (RMS)
π
…. (19)
…. (20)
≅ 1.11 (average value)..(21)
≅ 0.9 · (RMS value) ………… (22)
1 cycle
Fig 2-22
Iav, the direct current obtained by half - wave rectification of a sinusoidal alternating current I,
is expressed as follows by transformation of (19) and (20) :
2 × ⎛⎜ 2 × 1 I ⎞⎟
2 ⎠
⎝
Iav =
= 2 I = 0.45I
π
π
( I = 1 Iav = 2.22Iav )
0.45
23
Rr (Known Resistance)
2-10 Principle of an ohm meter
I0, the electric current that will flow through
the circuit when the SW is turned on in the
circuit designated in Fig 2 - 23, is
adjuster
I 0 = E ………… (23)
RT
When the SW is turned off, RX will be
included in the circuit in serial and hence
I=
I
E
……. (24)
RT + RX
The ohm meter of a tester uses the reduction
of the electric current to calculate the value
of RX.
From (23) and (24), P, the ratio against I0, is
E
+
R
RX
RT
P= I = T
=
….(25)
I0
E
RT + RX
RT
Rx (Unknown Resistance)
Fig 2-23
From (25),
⎛1
⎞
R X = RT • ⎜ − 1⎟ ……….………(26)
⎝P ⎠
When P, the ratio of I , is assumed to be 1/2, (26) becomes
I0
⎞
⎛ 1
R X = RT • ⎜
− 1⎟ = RT ………….. (27)
⎝ 1/ 2 ⎠
This suggests that the 50% point (1/2) of the effective meter deflection angle is the internal
resistance of the ohm meter. The Ω scale of a tester can be calculated from (25).
[Example 7]
When the internal resistance of a tester (RT) is 10.4k Ω, what percent does the point of 5k Ω
correspond to of the effective meter deflection angle ?
(Answer) From (25),
P=
24
RT
10.4kΩ
× 100 =
× 100 ≅ 67.5(%)
RT + RX
10.4kΩ + 5kΩ
2-11 Color code and rating code
There are certain agreements on the method of indication for resistors and capacitors.
Color code and rating code are described in this section. Color code is mainly used for resistors,
while rating code is used for capacitors.
1 Example of indication of a precision resistor
5
0
k
0
± 1%
5
0
0 0 0 0
5
0
3
0
1
Green Black Black Orange Brown
2 Example indication of a general
resistor (for household use)
5
0
0
k
± 5%
5
0
0 0 0 0
|
5
0
4
± 5%
Green Black Yellow
Gold
First
Second
Third
Fourth
Fifth
color band color band color band color band color band
First
Second
Third Multiplier
Tolerance
number
number
number
factor
Black
0
100
Brown
1
101
± 1%
Red
2
102
± 2%
Orange
3
103
Yellow
4
104
Green
5
105
Blue
6
106
Purple
7
107
Grey
8
108
White
9
109
Gold
10-1
± 5%
Silver
10-2
± 10%
Color
First color band
Fourth color band
First number
Tolerance
Second color band
Third color band
Second number
Multiplier factor
Fig 2-25
How to relate the color and number for remembering (in Japanese)
Fig 2 - 24
Tolerance code
B : ± 0.1 %
G:± 2%
C : ± 0.25 %
J:± 5%
D : ± 0.5 %
K : ± 10 %
F:± 1%
M : ± 20 %
3 Example of indication of capacitors
Capacitance tolerance code
K : means ± 10%.
0.022 μ F ± 10%
Rating code 1H 2 2 3
DC50V
2 2 0 0 0 pF
(Example)
DC50V
0.022 μ F
Fig 2 - 26
Rated voltage code
0 J : 6.3V
1 C : 16V
1 E : 25V
1 H : 50V
2 A : 100V
2 D : 200V
25
III Tester Assembly
As seen in the tin-lead phase diagram, the
conditions around point C are beneficial for
soldering of electronic components that are
easily affected by heat. Point C is called the
eutectic point and the solder of 62 - 63% tin,
37 - 38% lead is called the eutectic solder.
A solder of 60% / 40% is used for general
electric appliances. Since this set of
conditions has a range of semifluid phase
(215°C - 183.3°C = 31.7°C), it takes some
time for the solder to set.
This is the reason why you should never
move the material immediately after
soldering. Other solders include solders for
tins, low-lead solder for food use in view of
hygiene, etc.
Phase diagram of Sn-Pb solder
Temperature
3-1 Properties of soldering
Temperature most
suitable for soldering
(temperature higher by
50 - 60°C than ACE)
Liquid
Semifluid
Solid
Solid Semifluid
Solid
Tin
Lead
For tin For electric
works appliances
For
tableware
Fig 3-1
Point A …. Melting temperature of lead : 327.4°C
Point E …. Melting temperature of tin : 231.9°C
Point C …. 61.9% tin – 38.1% lead
Melting temperature : 183.3°C
Point F …. 50% / 50% tin / lead
Melting temperature : 215°C
3-2 Soldering Method
1 Preparation
(a) Clean the tip of the soldering iron. Judge if the temperature of the tip is suitable for
soldering. How to judge : the temperature is too high if the tip repels solder ; the temperature is
too low if solder melts slow and gives a matt finish. Change the length of the tip for
temperature adjustment.
(b) Remove grease, dirt or rust from the part to be soldered.
(c) Apply solder beforehand separately to both of the parts to be soldered together
(pre-soldering) if soldering or mounting of the components is difficult.
2 How to use resin flux cored solder
The ordinary way to apply resin flux cored solder is as
follows : Hold the solder iron in your dominant hand
and solder in the other hand. Follow the procedures
shown in the illustrations 1 to 6 in Fig 3 - 2 : Preheat
the part to be soldered with the solder iron, deliver
the solder to the boundary of the solder iron and
the part preheated. Sweat the solder at a needed
amount and then detach the solder. Carefully look at
the flow of the molten solder when you detach
the solder iron. The crucial point is when to detach
the solder iron.
Resin flux cored solder
Solder iron
Fig 3-1
[Procedures]
Apply the
solder iron to
the material.
Put the solder
onto the
boundary.
Sweat the solder Detach the
by 3 - 4 mm.
solder.
Fig 3-2
26
Detach the
solder iron.
Leave the
material to cool.
3-3 Soldering practice
KIT - 8D has a small board for soldering exercise.
Deliver the solder into the part for soldering on
this board to practice soldering. Cut the part off
after training.
Do not use this part for practice if you use the
optional buzzer kit. (Use the part without
holes for practice, the part at the right hand
side when you place the circuit board in
a direction shown in the figure.)
Patterns for
soldering
exercise
Fig 3-3
3-4 Preparations for assembling
1 Tools required
Check
Name
Soldering Iron
Tweezers
Radio Pliers
Nippers
Note
20 - 30W
Check
Name
+ Phillips Screwdriver
Hand file
Either of these
(Small size)
Scissors
(Small size)
Note
(Middle size)
For maintenance
of the iron tip
Prepare as needed
2 Verification of the components
Take the components out of the package and collate them with the parts list.
Check Symbol
b
c
Item name
Set of resistors and
diodes
Battery terminal
Battery fittings
d
Switch brush
1
o
with the meter and the
range selector knob)
1
e
f
Fuse fittings
Mini fuses 0.5A / 250V
2
2
p
q
1
1
g
Capacitor 0.022μ F
1
r
h
Zero Ω adjuster 10k Ω
1
s
i
Knob for zero Ω adjuster
1
t
j
Case stopper screw
1
k
Solder
1
Case
Protection cover
AA size batteries
(UM-3)
Test leads
(red & black)
Hand strap
Resistor for
checking 100 Ω
Resistor for
checking 22k Ω
a
Quantity Check Symbol
Item name
Quantity
1
l
Printed board
1
1
2
m
n
Dial plate
Name sticker
Panel (already mounted
1
1
2
One pair
1
1
1
27
3-5 Assembling and wiring
1 Caution for assembly and wiring
Do not turn the switch knob before assembly. The ball and spring included inside may leap out.
a) Read the cautions well and perform assembly and wiring in the order given.
b) The panels are made of resin and may melt and deform when in direct touch with the solder iron.
c) Make sure of the position when you stick on the dial and name sticker.
d) Solder quickly so as not to overheat the printed board.
2 Wiring and assembly of the printed board
2-1 How to wire and assemble
You can assemble this product in different ways as described below. You can choose one of the
following ways as you desire :
A) Assemble in the order of the parts list
This method is beneficial if you want to assemble the product quickly.
B) Assemble by referring to the layout plan
This method is helpful in learning how to read the color code of the resistors.
C) Assemble in the order of the circuit structure
This method allows you to assemble while understanding the circuit of the tester.
A) Assemble in the order of the parts list
Set up the resistor mount sheet as described below. After setting up, go to the process 2-2.
<Procedures for setting up>
Parts list sheet
Resistor mount
sheet
Peel off
1 Cut out the parts list sheet printed in Page 61.
2 Fold the top and bottom of the sheet. Peel off the films of the double-faced tapes.
3 Stick the tapes to the parts list sheet so that the resistors come to the upper side and the
diodes to the lower side. (Completion of the resistor mount sheet)
B) Assemble by referring to the layout plan
Take the resistor set and the printed board out of the parts bag. Start from the process 2- 2.
Install the components by referring to the component layout plan designated in Page 39.
C) Assemble in the order of the circuit structure
Refer to the assembly procedures described on Page 40 onwards.
28
2-2 Bending of the lead wires of the components
It is very convenient to bend the lead wires of
the components using the small board when you
mount the components to the printed board. Put
the body of a resistor or a diode into the square
hole of the small board as shown in Fig 3-5.
Press the resistor or the diode with your thumb
and bend the lead wires in the right angle by
forcing the lead wires to the edge of the small
board using the other hand. In this way the
components can be processed to fit to the
printed board. This processing can also be done
using tweezers or radio pliers.
① ····· 12.5 mm
② ····· 20 mm
Small board
R1 - R12, R14 - R18, D1-D7
R13 only
Fig 3-5
Note) Place the diode so that the body comes to the center of the square
hole when you bend the wires of D1-D7 because the hole is too large
for these diodes.
2-3 Soldering of the components
Insert the bent lead wires of the components into the printed board and solder them.
Repeat the bending and mounting processes for one component at a time : Bend the lead
wires of a component and mount it, and then bend the wires of the next component, and
so on.
※ Bend the lead wires a little to ease soldering.
Nipper
Solderin
Board
(silk-screen printed side)
Resisto
ca. 1 mm to 1.5
mm
Fig 3-6
Order Check No.
1
I
2
II
3
III
Operation
Insert the wires processed according to ②-2 into the predetermined
position from the back side (silk-screen printed side) of the board.
(See Fig 3 - 6)
Mount the component by soldering the solder side (green side) of the
printed board. Take care not to apply too much solder.
Cut the redundant lead wires off using nippers. Repeat the processes
I - III until all the components are mounted.
Insert so that the
cathode mark (band)
comes to the same
direction as the print.
Printed board
(silk-screen printed side)
Silk-screen print
Note : Polarity of diode
Diodes have polarity. Mount them in
the same direction as designated in
the silk-screen print (white print) on
the printed board.
Mounting of a diode (example for D1)
29
Note
Take care not to overheat the board or apply too much solder when soldering.
Do not move the components until the solder is set.
3 Mounting of capacitor
a) When assembling in the order of the parts list or the circuit structure
Insert the component into C1 of the printed board and mount it.
b) When assembling referring to the layout plan
Find the place of C1 in the layout plan on Page 39. Insert the component into the printed
board and mount it.
Soldering
Nippers
(Solder side :
green)
Board
(silk-screen
printed side)
ca. 1 mm to
1.5 mm
Fig 3-7
Order Check No.
4
I
5
II
6
III
Operation
Insert the capacitor into the position from the silk-screen printed side of
the board.
Solder the terminals of the capacitor from the solder side (green side) of
the printed board.
Cut the redundant terminal wires off using nippers, leaving
ca. 1-1.5 mm margin.
4 Installation of zero Ω adjuster
Order Check
7
Note
Operation
Insert the zero Ω adjuster from the solder
side (green side) into the printed board and
solder it. (See Fig 3-8)
The appearance after installation is
illustrated in Fig 3-9. (The adjuster is
mounted on the other side of the resistors.)
Mount the zero Ω adjuster so that it is not tilted. Check
once before soldering if it is tilted. The adjuster will
rub the hole of the panel and will not turn smoothly
if it is tilted.
Solder side
Fig 3 - 8
Resistor
Fig 3 - 9
30
Insert port
Soldering
5 Installation of fuse holders
Order Check
Operation
Insert the fuse holders from the solder side (green side) into the printed board
and solder them. (See Fig 3-10)
8
Printed Board
Place to
install fuse
holders
Note
(Solder side : green)
Be careful of the direction of the nails
when inserting the fuse holders.
It is convenient to use the edge of the
desk when soldering the fuse holders.
(See Fig 3-11)
(Enlarged View)
Nail
(Desk)
Fuse holders
Be careful of
the direction of
the nails
Soldering
(Solder side : green)
Fig 3-11
Resistor
Fig 3-10
6 Installation of battery fittings
(Insert here)
(Solder side)
Resistor
Soldering
Resistor
Fig 3-12
Order Check No.
9
I
10
II
11
III
Note
Operation
Insert the battery fittings from the solder side (green side) of the
board. The place of mounting is on the upper-left side when seen
from the solder side of the board.
From the position ① (illustrated in dotted lines), turn the fittings so
that they are straight along the printed boards as shown in the figure.
Solder firmly at the position shown in the figure.
Make sure of the direction when you insert the battery terminal.
In the case that the open part of the battery fitting is crushed, restore the shape to its
original state by using your fingers. Connection between the battery and the fitting may
fail if the fitting is left deformed.
31
7 Installation of fuse
Order Check
12
Operation
Mount a fuse on the fuse holders as shown in
the figure. (One of the two fuses included in
the package is the spare fuse and will be
installed in the later process.)
Fig 3-13
<Installation of fuse>
8 Installation of test leads
Order Check
13
Note
Operation
Put the red test lead through the hole at the
fuse holder side of the printed board; put the
black test lead through the hole at the
position shown in the figure.
Bend the core wires down to the printed
board side. Solder the wires.
Insert the test leads from the back side of the printed board
(silk-screen printed side).
Fuse holder
(Red test lead)
Fig 3-14
(Black test lead)
Assembly check (I) Assembly of the printed board
Inspection Corresponding
Article
Check
②-3
④
⑤
⑥
⑦
⑧
②-3 ~ ⑥
and ⑧
Items to be checked
Is there any mistake in mounting of the resistors and diodes ?
(Position of installation, polarity of the diodes, etc.)
Is the zero Ω adjuster inserted from the solder side (green side) ?
Is the zero Ω adjuster installed without tilt ? (See Fig 3-9)
Are the fuse holders inserted from the solder side (green side) ?
Is the direction of the nails of the fuse holders correct ?
(See Fig 3-10)
Are the battery fittings installed without tilt ? (See Fig 3-12 II)
Are the battery fittings not crushed ? (See ⑥ Note)
Have you not forgotten to install the fuse ?
Are the positions of installation of red and black test leads correct
(not reversed) ?
Are the red and black test leads inserted from the silk-screen
printed side of the printed board ?
Is the soldering well done ?
Have you not forgotten to solder any component ?
If you find anything wrong through the inspection check, see the assembly procedures in the
corresponding article and correct to solve the problem. Proceed to the next procedures only
after inspection is finished. Progress in the same way for the rest of the processes and
inspections.
32
k Installation of switch brush
Order Check
Operation
14
Install the switch brush onto the range selector knob mounted on the panel.
Switch brush
Place to install
Panel
Range selector
knob (inside)
Fig 3-15
1
2
3
4
Turn the range selector knob to align the positions of Ⓐand Ⓑ as illustrated below.
Direct the switch brush so that the mark on it comes to the upper-left side.
Hook the switch brush first to the projections at the left hand side of the range selector knob.
Press the right hand side of the switch brush with your fingers to install.
2 Locate the mark to
Note
Mark
4 Press the right hand side
The correct direction
(as shown in the figure).
of the brush with your
finger.
Note
Do not push
too hard.
3
Fig 3-16
1 Align the positions
Hook the brush
on the projections
at the left hand side.
Projections on the knob
(place to install)
Fig 3-17
of Ⓐand Ⓑ
Note
Do not push the brush at the contact points
from directly above when fitting the switch
brush into place.
It may cause deformation of the switch brush.
Contact Points
Fig 3 -18
33
Assembly check (II) Installation of switch brush
Inspection Corresponding
Check
Article
⑨
Items to be checked
Is the mark of the switch brush in the correct direction ?
(See Fig 3-16)
Do the contact points of the switch brush have the same height ?
(They should not be crushed).
This height shall
be uniform.
Soldering of meter leads
Order Check
15
Operation
Put the red lead wire coming from the
meter through the position of “M +” ; put
the black lead wire coming from the panel
through the position of “M -”. Solder the
wires.
Black
(Meter)
Red
Solder the core wires after bending the wires to the printed
board side (solder side).
Fig 3-19
⑪ Installation of the completed printed board
Order Check
16
Operation
Install the completed printed board onto the panel. Fasten the printed board
by the three nails on the panel as shown in the assembly diagram.
Completed printed board
Panel
Fig 3-20
34
Hold the panel in your hands as illustrated below. Position the completed printed board roughly
1 and put it onto the panel lightly.
2
3
4
Note) Hold the panel in your hands when you fasten the board.
Beginning from part Ⓐ of the figure below, push the nail with your thumb to the direction
indicated by the arrow in the figure.
With the nail still pressed, push the printed board into position with the other hand.
Repeat the processes for part Ⓑ and part Ⓒ, one at a time ; pushing the nail in the direction
indicated in the figure, push the board into position in the same way as for part Ⓐ.
②
Note
Push the nail in the direction
indicated by the arrow.
Do not push too hard.
(The support rod may break.)
Fig 3-21
③
Locate your thumb as near to the
nail as possible and press the
printed board downwards.
Note
Do not try to fasten the printed board at a time by
placing the panel on a desk, with the meter part
facedown, as illustrated in Fig 3 - 22. Be careful not to
press the range selector knob when you hold the panel
within your hands to fasten the printed board ; the knob
Fig 3-22
may come off if pressed.
In the case that the knob has come off, reinstall the
knob following the installation method for the range
selector knob described in Page 39.
Do not place the panel
on a desk to press the
board at a time.
Desk or table
Do not push the knob.
⑫ Arrangement of test leads
Black test lead
Red test lead
Black test lead
Black test
lead
Make the leads the
same length from here.
Red test lead
Red test lead
Fig 3-23
Order Check No.
17
I
18
II
19
III
Operation
Straighten the red test lead to the left hand side. Push the red lead into
the ditch of the panel shown as the shaded portion in the figure.
Adjust the length of the black lead so that the length from the outlet of
the lead presser becomes the same as that of the red lead. Hold the
outlet part temporarily.
Push the black lead firmly into the ditch shown as the shaded portion
in the figure.
35
Note
Adjust the length of the test leads so that the length from the outlet of the lead presser
becomes the same for both red and black leads.
Lightly pull the leads after arrangement of the leads to check if they do not come out.
⑬ Installation of dial plate and zero Ω adjuster knob
Order Check
20
21
Note
Zero Ω adjuster knob
Operation
Peel the back side sheet off from the dial
plate and stick the dial plate onto the panel
in the position shown in the figure.
Put the zero Ω adjuster knob along with
the shaft of the zero Ω adjuster and snap
into the position shown in the figure.
Stick the dial plate on slowly and calmly. If the dial is
attached in the wrong position, pull it off slowly from
the edge and try to stick it on again.
Check if the zero Ω adjuster is tilted when the knob
cannot be fitted easily.
Position to stick
the dial plate on
Fig 3-24
⑭ Mounting of batteries and battery terminal
Order Check
22
23
Operation
Install the battery terminal in the position in the panel as shown in the figure.
Place firmly and be careful of the direction, which edge is the top or the
bottom (Fig 3-25).
Install two AA size dry batteries. Be careful of the polarity of the batteries.
(Fig 3-26).
Fig 3-25
<Installation of the battery terminal>
36
Fig 3-26
<Installation of the batteries>
⑮ Mounting of spare fuse
Order Check
24
Operation
Insert the spare fuse into the spare fuse case
on the panel.
Spare fuse case
Fig 3-27
Assembly check (III) Assembly of the panel
Inspection Corresponding
Check
Article
⑩
⑪
⑫
⑬
⑭
⑮
Items to be checked
Are the red and black meter lead wires connected to M+ and M-,
respectively ?
Do the lead wires of the meter not come out when pulled lightly ?
Is the printed board fastened tightly by the three nails of the panel ?
Is the test lead not pinched between the panel and the printed
board ?
Are the test leads fitted firmly into the position of installation of the
panel ?
Is the dial plate not stuck too far from the position to be placed ?
Have you not forgotten to install the zero Ω adjuster knob ?
Does the zero Ω adjuster knob turn smoothly ?
Have you not forgotten to install the batteries or the battery
terminal ?
Is the polarity of the batteries correct ?
Have you not forgotten to mount the spare fuse ?
⑯ Installation of hand strap and rear case
Order Check
Operation
25
Attach the hand strap to the panel as illustrated in the figure. (Fig 3-28)
Fit the rear case into the panel from the bottom. Align it with the panel and
26
insert the case stopper screw into the place shown in the figure. Screw it with
a Phillips screwdriver. (Fig 3-29)
Case stopper screw
(M4 × 10 screw)
Hand strap
Hook the strap
around this pin.
Fig 3-28
Installation of the hand strap
Fit the case into the
panel from here.
Fig 3-29
Installation of the rear case
37
Rear case
⑰ Attachment of name sticker
Order
Check
27
Operation
Attach the name sticker on the rear case in
the position designated in the figure and
write your name on it.
(Place to attach
the sticker)
Fig 3-30
⑱ Storage of the test leads
Order
28
Note
Check
Operation
Put the test leads into the storage space at
the main body. Put the test pin side in
first when storing.
The test leads are tied up. Loosen the bundle when storing.
Fig 3-31
⑲ Installation of protection cover
Order
29
Check
Operation
As illustrated in Fig 3-32, insert the installation pin inside
the cover into the ditch and slide it to the direction
designated by the Arrow 1. After sliding, close the cover in
the direction designated by the Arrow 2. Do not press the
cover down from above as shown in Fig 3-33 ; this may
break the cover.
Fig 3-33
Fig 3-32
Assembly check (IV) Finish
Inspection Corresponding
Check
Article
⑯
⑰
⑱
⑲
Items to be checked
Have you not forgotten to attach the hand strap ?
Is the main body fastened firmly with the case stopper screw ?
Have you not forgotten to attach the name sticker ? (Fill in your
name)
Are the test leads stored in place ?
Is the body cover installed correctly ?
Now assembly is completed.
38
Component layout plan
Meter black lead
Meter red
lead
Test lead black
Test lead red
Fig 3-34
Installation of the range selector knob
For KIT-8D, the range selector knob is already
incorporated into the panel.
In the case that the range selector knob has come
off during assembly procedures, follow the
procedures below to reassemble:
SW knob
(Fig 1)
②
Adjust the positions
of these parts
- Procedure for installation ① Insert the coil spring into the hole at the side
of the range selector knob. (Fig 1)
② Place the range selector knob lightly onto
the place of installation of the panel. Adjust
the position of the range selector knob so that
the hole to which the spring has been inserted
and part A shown in the figure come together.
(Fig 2)
③ Place the still ball on part A. (Fig 3)
④ Press the knob from the above. (Fig 3)
Coil spring
(Fig 2)
(Fig 3)
39
C) Assemble in the order of the circuit structure
Assembly procedures
1) Perform the processes 4 to ⑨ , ⑬ , installation of the dial plate, and installation of
the battery terminal in process ⑭.
2) After completion of the above processes, mount the components by referring
to the processing procedures described in processes 2-2 and 2-3.
3) Always displace the soldering of the meter lead out of the printed board and dismount
the printed board from the panel when you proceed to the next circuit structure.
(See How to displace the printed board, Page 42)
Note)
You may attach the circuit components onto the parts list sheet; you may otherwise refer to
the component layout plan illustrated on Page 39.
Do not force open the printed board. Unlock the nails of the panel one by one when you
displace the board.
The figures below and the layout plan of the printed board show the pattern side (green side)
of the printed board. Insert the components from the silk-screen printed side of the printed
board and solder from the green side when you mount the components.
… Meter Circuit Mount the meter protection circuit, D3 - D5 and C1, resistors R1, R2 and
R18. Wire the meter leads.
Note) SW symbol means that each
contact point is connected
by the brush.
… Direct Current Ammeter Install the shunt resistors R10 (3mA), R11 (30mA) and R12 (0.3A).
40
… Direct Current Voltmeter Mount R3 (3V), R4 (12V) and R17. Install R5 to R9, which
are common with the multiplier of the alternating current
voltmeter.
… Alternating Current Voltmeter The multiplier components, common with the direct
current voltmeter, have already been mounted.
Install rectifier diodes D1 and D2.
… Ohm Meter
Install the serial resistor R16 and the shunt resistors R13 (×1), R14 (×10)
and R15 (×1k). Mount the diodes for circuit protection, D6 and D7.
41
… Battery Check The battery check circuit is the one that R3 and R13 is added to the meter
circuit. No wiring is needed since these are already mounted.
How to displace the printed board
① First, dismount the zero Ω adjuster knob
before displacing the printed board.
② As shown in the right figure, pull the printed
board lightly using your index finger while
pressing the nail on the panel of the part Ⓐ
in the direction designated by the arrow using
your thumb until you hear a click that
indicates the board has come off.
③ Undo nails Ⓑ, and then Ⓒ, one by one, in the
same way as Ⓐ.
④ Remove the meter leads, red and black.
Note
Do not push the nail too hard with your
thumb.
The support rod (nail) may break.
Be careful when you pull the printed board
with your index finger. The meter lead wires
or other wiring may be disconnected if you
pull off the board too hard.
The pattern on the printed board may be
disconnected if you force to displace the
printed board without dismounting the zero
Ω adjuster knob.
42
※ Pull the printed board
with your index finger
while pushing the nail
of the panel with your
thumb.
IV Operation test and calibration
4-1 Quick operation check
The circuit of this product does not require adjustment. Assembly and wiring of the product
will simply provide the tolerance range described in the specifications. The product is thus
ready to be used as a normal circuit tester after simple operation check.
Operation check requires resistors (100 Ω and 22k Ω), commercial power supply (100V), and a
dry battery (take the battery out of this meter if you do not have one). (The resistors for
checking are included in the parts bag.)
Check the meter by following the procedures described below. Fill in the measured value or a
check mark “ ” in the blank square
provided in the following descriptions :
1 Preparation of measurement
Meter zero adjustment
Turn the meter zero adjuster using a screw driver so that the needle indicator of the meter
comes to the point of zero correctly when electricity is not applied to the circuit meter.
2 Check of the DCmA range (the value of resistance in the parentheses in the equation
below is the internal resistance of each range.)
(a)
DC60μA range : Check the meter reading using a dry battery and a 22k Ω - resistor for
checking. (ca. 59μ A)
(Red)
(Black)
※ Measurement will be facilitated by making a
circuit illustrated in Fig 4 - 1 using a battery
compartment, discrete circuit board, etc.
I=
ca.1.6V
≅ 59 μA
22kΩ + (5kΩ)
Fig 4 -1
(b)
DC3mA range : Check the meter reading using a dry battery and a 22k Ω - resistor for
checking. (ca. 0.07mA)
I=
(c)
DC30mA range : Check the meter reading using a dry battery and a 100 Ω - resistor
for checking. (ca. 14.5mA)
I=
(d)
ca.1.6V
≅ 0.07 mA
22kΩ + (100.5Ω)
ca.1.6V
≅ 14.5mA
100Ω + (10.5Ω)
DC0.3A range : Check the meter reading using a dry battery and a 100 Ω - resistor for
checking. (ca. 15.8mA)
I=
ca.1.6V
≅ 15.8mA
100Ω + (1.5Ω)
43
3 Check of the DCV range (observed value ; the value in the parentheses is the voltage of
the battery included in this kit)
(e)
DC 3V range : Measure the battery voltage and read the meter.
(ca. 1.6V)
(f)
DC 12V range : Measure the battery voltage and read the meter.
(ca. 1.6V)
(g)
DC 30V range : Measure the battery voltage and read the meter.
(ca. 1.6V)
(h)
DC 120V range : Measure the battery voltage and read the meter.
(ca. 1.6V)
(i)
DC 300V range : Measure the battery voltage and read the meter.
(the needle twitches a little to the right)
4 Check of the alternating current voltage
Warning
1. Always use a commercial power supply (101 ± 6V) to which a circuit breaker is incorporated.
2. Do not hold the test leads over the brim at the test pin end when measuring.
(j)
(k)
(l)
(m)
(n)
AC120V range : Measure the commercial power supply and read the meter.
(ca. 100V)
AC300V range : Measure the commercial power supply and read the meter.
(ca. 100V)
AC600V range : Measure the commercial power supply and read the meter.
(ca. 100V)
AC30V range : Measure the1 battery voltage and read the meter.
(ca. 3.2V)
(Note) The meter reading will be zero when the polarity is reversed.
AC12V range : Measure the battery voltage and read the meter.
(ca. 3.2V)
(Note) The meter reading will be zero when the polarity is reversed.
5 Battery check range (check of
(o)
1.5V
range
1.5V
)
: Measure the battery voltage and read the meter.
(ca. 1.5V)
6 Check of resistance range (Restore the dry battery that has been used in check of DC
voltage and current to the tester.)
(Note) Perform zero Ω adjustment for each range.
(p)
Ω × 1k range : Measure the 22k Ω - resistor for checking and read the meter.
(22k Ω)
(q)
Ω × 10 range : Measure the 100 Ω - resistor for checking and read the meter.
(100 Ω)
(r)
Ω × 1 range : Measure the 100 Ω - resistor for checking and read the meter.
(100 Ω)
The checking procedures described above will provide the way to judge whether any of the
range is in good condition or not. Check of the DC600V range can be omitted by performing
AC600V range check and hence not described above.
(Note) In the check items (m) and (n), DC voltage is measured using ACV range ; note that
this procedure is not a measurement but is carried out for the purpose of checking
the meter indication.
44
4-2 Calibration of the tester
Calibration is carried out to see if the assembled tester satisfies the accuracy as in the
specifications. If the tester passes this examination, a highly reliable measurement is promised
when you use it. In the case that the tester does not show the performance described in the
specifications, there is a need to check if the correct resistances are mounted at the specified
positions. Modification may also be needed including replacement.
1 How to calibrate
The ordinary way to calibrate a measuring instrument is to adjust the indication of the
instrument to be examined to the calibration scale and read the value of the standard device;
calibration of testers also adopts this strategy. When calibration results are expressed in relative
errors (see Page 43), M corresponds to the indication of the tester while T corresponds to
the reading of the standard device.
Though JIS-C-1102 prescribes how to adjust the indication, description is omitted here because
the tolerance of testers is large. The following illustrations show how to connect the devices :
(b) DC Ammeter
(a) DC and AC Voltmeters
Variable
Voltage
Generator
Variable
Voltage
Generator
Standard Device
(Class 0.5 or higher)
Standard Device
(Class 0.5 or higher)
Tester to be examined
Tester to be examined
(c) Ohm Meter
Tester to be examined
Standard Resistor
2 Tolerance of a tester
Note that the tolerance of a tester is expressed as a value against the maximum scale value, not
against the scale reading. For example, since the tolerance of the DC120V range of this product
is within ± 3% of the maximum scale value,
120V (maximum scale value) × ± 3% = ± 3.6V
Therefore, the tolerance range is ± 3.6V.
This value of tolerance range will apply to each of the points of graduation.
The tolerance of the resistance range, ± 3% of the scale length, can easily be understood if
converted to the V.A scale (± 1.8 graduation of the V.A scale). The point of 50% (V.A scale) is
usually used in checking an ohm meter.
3 Errors
An “error” is prescribed in JIS-C-1002 as “the difference between the measured value, setting
value or rated value and the true value of the quantity measured or supplied. (The magnitude of
an error is expressed in absolute error, relative error or percentage error.)” A measuring
instrument has an error due to the instrument itself (error : ε), such as of accuracy of the
components ; the relationship between the measured value M and the true value T is expressed
as follows :
Absolute error ε = M - T
45
ε 0, the relative error that indicates how large the absolute error is compared to the true value, is
Relative error ε 0 =
ε
T
× 100 =
M−T
× 100(%)
T
For example, when the scale reading was 105V and the true value is assumed to be just 100V in
measurement of the 100V - alternating current at the AC 300V range, the error is
Relative error ε 0 =
105 − 100
× 100 = 5% .
100
4 Items to be calibrated
In the calibration of a tester, the maximum scale value of each voltage or current range and the
central scale value of each resistance range (20 Ω, 200 Ω and 20k Ω for this product) are the
calibration points. Other than this, a graduation characteristic test may be carried out to examine
if the meter indicates in accordance with the scale graduation. Ten points, from 10% to 100% in
steps of 10%, of the lowest current range (60μ A for this product) are usually subjected to this
test. This is to examine the dispersion of graduation profile (linearity) of the meter. Data for
AC12V scale may be collected as a graduation characteristic considering the effect of the
rectifier.
4-3 Measurement results
1 Calibration of voltage and current (maximum scale value)
Date of examination :
Range
DC 600V
300V
120V
30V
12V
3V
0.3V
DC 0.3A
30mA
3mA
(60μA)
AC 600V
300V
120V
30V
12V
46
Reading of
the tester
(M)
Reading of the
standard device
(T)
Absolute error
ε = M-T
Conditions
°C
Relative error
M−T
ε0 =
× 100(%)
T
%
2 Calibration of the ohm meter (indication)
Reading of
Reading of
RT
RT
× 100% the standard T ' =
× 100% Relative Error
Range the tester M' =
ε 0 = T’ - M’ (%)
R
+
M
R
+
T
T
T
(M)
device (T)
50%
Ω × 1k
20k Ω
50%
Ω × 10
200 Ω
50%
Ω×1
20 Ω
(Note) R T : the central scale value of the resistance range (internal resistance)
3 Calibration of the meter graduation characteristics (indication of DC60μ A range)
Reading of
Reading of
T
Relative Error
× 100%
M' = M60μA × 100(%) the standard T' =
the tester
ε
T
0 = M’ - T’ (%)
100
(M)
device (T)
DC 60 μ A
54 μ A
48 μ A
42 μ A
36 μ A
30 μ A
24 μ A
18 μ A
12 μ A
6μA
100%
90%
80%
70%
60%
50%
40%
30%
20%
10%
(Note) T (100) : reading of the standard device at the point of 100% (T)
4-4 Summary of the results
Plot the measurement results of 4-3 in a graph by defining ⊕ as an over deflection and ⊝ as an
under deflection against the value of the standard device.
(Note) Use the scale of ( ) % for the plot of graduation characteristic because it gives small errors.
Graduation Characteristic
Maximum Scale Value
50% Value
47
V Circuit calculation of the tester
5-1 Meter Circuit
Meter Protection Circuit
The meter used in the tester is a moving - coil
type as described earlier.
This moving coil is formed by rounding a
copper wire of 0.02 - 0.04 mm thickness
hundreds of times and it is therefore difficult
to make a coil have a constant resistance value
(internal resistance).
Since copper wire has a temperature
coefficient of ca. + 0.4% against an increase in
temperature of 1°C, compensation of this
change by the circuit is needed. Some high class testers use a thermistor (which has a
temperature characteristic opposite to that of
copper wire) to compensate the temperature
change. This product is designed to realise a
Fig 5-1
non-adjusting
system;
a
resistor
is
Im = Meter circuit current ; Rm = Meter circuit resistance ;
incorporated to the meter coil circuit in serial
im = Meter current sensitivity ; Em = Voltage between terminals
connection so that the ratio of the change
becomes very small compared to the whole
circuit.
Meter circuit specifications : meter current sensitivity (im) ············· 48 μ A ± 1%
meter internal resistance (r) ·············· 2k Ω ± 8%
working current of DC voltage & current (Im)·· 50 μ A
voltage between A and B (Em) ············ 300mV (0.3V)
In the meter circuit shown in Fig 5-1, VR + R 18 will act as a shunt that magnifies im into Im.
Therefore, when this resistance is defined as R 0, the equation (18) in Page 22 becomes
n=
I0
I
Where n = magnification factor
I = current before magnification = im
I 0 = current after magnification = Im
n=
I 0 Im * * * *μA
=
=
≅
I im * * * *μA
.
R0 =
* * * * kΩ
r
=
≅ * * * * kΩ
n −1 **** −1
(round to the nearest integer : round up if the first digit of the fractional part is 5 or larger ;
round down otherwise.)
When the zero Ω adjuster VR is 10k Ω (see 5 - 5 Ohm meter (Ω) circuit),
R 18 = R 0 - VR = ***** k Ω - ***** k Ω = ***** k Ω
From Ohm’s law, Rm is (from the specifications, Im = 50 μ A and Em = 300mV)
Em * * * * × 10 −3 V
Rm =
= * * * * ×10 3 Ω = * * * * kΩ
=
−6
Im * * * * × 10 A
R1 is hence
⎛ r × R0 ⎞
⎛ * * * * kΩ × * * * * kΩ ⎞
⎟⎟ = * * * * kΩ − ⎜⎜
⎟⎟
R1 = Rm − ⎜⎜
⎝ * * * * kΩ + * * * * kΩ ⎠
⎝ r + R0 ⎠
≅ ***** k Ω - ***** k Ω = ***** k Ω
48
5-2 DCA Circuit
I0 = Measured Current
Rm = Meter Circuit Resistance
The equation (18) for a shunt is used in
calculation of DC ammeter circuit. Ohm’s law
also provides the way to calculate.
1 DC60 μ A : from the equation (18) for a shunt,
I 0 I (60 μ ) * * * *μA
=
=
= ****
I
Im
* * * *μA
Rm * * * * kΩ
R2 =
=
= * * * * kΩ
n −1 **** −1
2 DC3mA :
I (3 ) * * * * × 10 −3
I
=
n= 0 =
= * * * * ×10 3 = * * * *
Im * * * * × 10 −6
I
n=
R10 =
Rm * * * * kΩ * * * * kΩ
=
=
≅ **** Ω
****
n −1 **** −1
3 DC30mA :
I (30 ) * * * * × 10 −3
I
=
n= 0 =
= ****
Im * * * * × 10 −6
I
4 DC0. 3A :
I (0.3 ) * * * * × 10 −3
I
=
n= 0 =
= ****
Im * * * * × 10 −6
I
R11 =
DC60 μ A - 0.3A equivalent circuit
Fig 5-2
※ For questions 2 to4, calculate to four decimal
places and round off (half - adjust) to convert into
the unit in the answer column.
Rm * * * * kΩ
=
≅ **** Ω
n −1 **** −1
′ Rm * * * * kΩ
R12 =
=
= **** Ω
n −1 **** −1
The actual circuit has a resistance of ca. 0.01Ω due to contact resistance of the switch or the
pattern of the printed board. This should be subtracted from the calculated value. (The resistance
is negligible for other ranges because the value of the shunt is large.) Then,
R 12 = R 12’ - 0.01 Ω = ***** Ω - 0.01 Ω = ***** Ω
5-3 DCV Circuit
The equations for a multiplier are generally used in calculation of DC voltmeter circuit. You can
otherwise use the value of Ω / V, indicated on the tester, to calculate the resistance of a
multiplier. Here, we will calculate using the equations for a multiplier.
Fig 5-3 Equivalent circuit of DC3V - 600V
49
1 DC3V
E (3 ) * * * *
E
n= 0 =
=
= ****
Em * * * *
E
R3 = Rm • (n − 1) = * * * * kΩ × (* * * * − 1)
2 DC12V
E (12 ) * * * *
E
n= 0 =
=
= ****
E
Em * * * *
R4 = Rm • (n − 1) = * * * * kΩ × (* * * * − 1)
= * * * * kΩ × * * * *
= * * * * kΩ
= * * * * kΩ × * * * *
= * * * * kΩ
3 DC30V
Because the same circuit as ACV is used for DC30V to DC600V, a shunt R 17 is incorporated in
the meter circuit in make them have the same sensitivity with ACV (9k Ω / V). The current
sensitivity of ACV9k Ω / V is
I (AC ) =
1V
≅ 111.1μA
9kΩ
The current sensitivity of DCV20k Ω / V is
I (DC ) =
1V
= 50μA = Im
20kΩ
Hence, from the equation (18) for a shunt,
n=
I 0 I(AC ) * * * *
=
=
= **.**
I
Im * * * *
R17 =
Rm * * * *kΩ * * * * kΩ
=
=
****
n −1 **** −1
= * * * * kΩ
(to one decimal place)
Here, calculation is performed for reference since the multiplier of DC30V to DC600V is
common with ACV. As seen from Fig 5 - 3, Rm of DC30V - DC600V has a circuit where R 17 is
incorporated in parallel. Defining this as Rm’ gives the following :
Rm × R 17 * * * *kΩ × * * * * kΩ
≅ * * . * * * *kΩ
=
Rm + R 17 * * * *kΩ + * * * * kΩ
E (30 ) * * * *
E
=
= ****
R(30 ) = Rm′ • (n − 1) = * * * * kΩ × (* * * * − 1)
n= 0 =
Em * * * *
E
= * * * * kΩ × * * * *
≅ * * * * kΩ (Round down the decimal point.)
′
(
)
Note) R (30 ) = R 5 + R 6 + Rm ; See the description of ACV.
Rm′ =
4 DC120V
E (120 ) * * * *
E
n= 0 =
=
= ****
Em
****
E
R(120 ) = Rm′ • (n − 1) = * * * * kΩ × (* * * * − 1)
R 7 = R (120 ) − R (30 ) = * * * * kΩ − * * * * kΩ = * * * * kΩ
5 DC300V
E (300 ) * * * *
E
=
= ****
n= 0 =
Em
****
E
R 8 = R (300 ) − R (120 )
50
= * * * * kΩ × * * * *
≅ * * * * kΩ (Round down the decimal point.)
R(300 ) = Rm′ • (n − 1) = * * * * kΩ × (* * * * − 1)
= * * * * kΩ × * * * *
≅ * * * * kΩ (Round down the decimal point.)
= * * * * kΩ − * * * * kΩ = * * * * kΩ = * * * * MΩ
6 DC600V
E (600 ) * * * *
E
=
= ****
n= 0 =
Em
****
E
R 9 = R (600 ) − R (300 )
R(600 ) = Rm′ • (n − 1) = * * * * kΩ × (* * * * − 1)
= * * * * kΩ × * * * *
≅ * * * * kΩ = * * * * MΩ
= * * * * MΩ − * * * * MΩ = * * * * MΩ (to two decimal places)
5-4 ACV Circuit
The meter of a tester indicates the average value.
From equation (21),
(root mean square value) = 1.11 (average
value)
This product adopts a half - wave rectification
circuit and hence, as shown in Fig 5 - 4, the
current will flow through the meter in the
direction from ⊕ to ⊝ by passing D 1, while the
current will pass through D 2 and will not flow
through the meter in the direction from ⊝ to ⊕.
This means the current that flows through
the meter will be half. Relationship between the
RMS value (I) and the average value (Iav) is
therefore
Fig 5-4 AC voltmeter principle
1
= 1.11 × Iav
2
∴ I = 2.22Iav
I×
Hence the alternating working current I is
I = 2.22 × 50 μ A = 111.1 μ A
Expression of this in Ω / V gives the following ; from Ohm’s law,
V
1
→ Ω/V =
Ω
A
1
1
∴
=
= 9 × 10 3 Ω / V = 9kΩ / V
−6
I(A ) 1.111 × 10 A
A=
We have used the equations for a multiplier in calculation of DC voltage circuit ; here we will
calculate using Ω / V.
1 AC12V (Ra = 2k Ω)
R (AC12 ) = 9kΩ / V × * * * * V = * * * * kΩ
R 5 = R (AC12 ) − Ra
= * * * * kΩ − * * * * kΩ = * * * * kΩ
This calculation does not include the effect of
the rectifier; the effect is corrected
experimentally by the AC12V - exclusive scale
graduation.
Fig 5-5 Equivalent circuit of AC12V - 600V
51
2 AC30V
R (AC30 ) = 9kΩ / V × * * * * V = * * * * kΩ
R 6 = R (AC30 ) − R (AC12 ) = * * * * kΩ − * * * * kΩ = * * * * kΩ
3 AC120V
R (AC120 ) = 9kΩ / V × * * * * V = * * * * kΩ = * * * * MΩ
R 7 = R (AC120 ) − R (AC30 ) = * * * * kΩ − * * * * kΩ = * * * * kΩ
4 AC300V
R (AC300 ) = 9kΩ / V × * * * * V = * * * * kΩ = * * * * MΩ
R 8 = R (AC300 ) − R (AC120 ) = * * * * MΩ − * * * * MΩ = * * * * MΩ
5 AC600V
R (AC600 ) = 9kΩ / V × * * * * V = * * * * kΩ = * * * * MΩ
R 9 = R (AC600 ) − R (AC300 ) = * * * * MΩ − * * * * MΩ = * * * * MΩ
5-5 Ohm meter (Ω) circuit
The key point in calculation of an ohm meter circuit is that the circuit uses a zero Ω adjuster to
compensate consumption of the batteries. The setting conditions for the ohm meter circuit are :
Adjustable range of the battery voltage
2.5V - 3.5V or more
Ω × 1k range : 20k Ω
Central scale value of the meter (internal resistance)
Ω × 10 range : 200 Ω
Ω × 1 range :
20 Ω
1 Zero Ω adjustment circuit
The lowest limit of the adjustable range of the
battery voltage, 2.5V, is the value to be adopted
when the remaining electricity of the batteries is
lowest. The zero Ω adjuster (VR) will be
adjusted to 0 Ω (Point “a”) in view of the role of
the variable resistance in the whole circuit.
From the equation of Ohm’s law (2), the
equivalent internal resistance R (2.5) between the
terminals is
R (2.5 ) =
E (2.5 )
=
* * * *V
* * * *μA
Im
* * * *V
=
= * * * * ×10 3
* * * * × 10 −6 A
Fig 5-6 Zero Ω adjustment circuit diagram
※ Here we use the actual value of
the circuit resistance, though R
18 is calculated to be 38kΩ on
Page 48.
Ω = * * * * kΩ
In Fig 5-6, the internal resistance between the Point “a” and the ⊝ terminal, Ra, is
Ra =
r ×R 0
* * * *kΩ × * * * * kΩ
≅ * * * * kΩ (to two decimal places)
=
r + R 0 * * * *kΩ + * * * * kΩ
Therefore, in order to make the meter work full-scale when E = 2.5V,
R 16 = R (2.5 ) − Ra = * * * * kΩ − * * * * kΩ = * * * * kΩ
52
For the highest limit of the adjustable range of the battery voltage, E (max), on the contrary, the
zero Ω adjuster will be adjusted to the full, 10k Ω (Point “c”). The internal resistance between
Point “c” and the ⊝ terminal, Rc, is
Rc =
(r + VR ) ×R 18
r + VR + R 18
=
(* * * *kΩ + * * * * kΩ ) × * * * * kΩ
* * * *kΩ + * * * * kΩ + * * * * kΩ
≅ * * * * kΩ (round off to the second decimal place)
When the meter is made to work full - scale, the voltage between the Point “c” and the ⊝
terminal is
Ec = I • R = im × (r + VR ) = * * * * μA × (* * * *kΩ + * * * * kΩ )
≅ * * * * ×10 −3 V = * * * * mV
The electric current that passes through R18, Ic, is
Ec * * * * × 10 −3 V
Ic =
=
≅ * * * * ×10 −6 A = * * * * μA (to one decimal place)
3
R 18 * * * * × 10 Ω
The current that flows from the batteries, I (max), is
I(max) = im + Ic = * * * * μA + * * * * μA = * * * * μA
From Ohm’s law, the battery voltage at the Point “c” of the zero Ω adjuster, E (max), is
E(max) = I(max ) × (Rc + R 16 ) = * * * * μA × (* * * *kΩ + * * * * kΩ )
≅ * * * * V (round off to the second decimal place)
The value thus satisfies the setting condition, 3.5V.
Next, we will look into the position of the brush of the zero Ω adjuster when the battery voltage
(initial voltage) is 3.2V. When we assume the position to be the Point “b” in Fig 5 - 6, we will
obtain the following from the conditions “0 Ω at 2.5V and 10k Ω at 3.6V” :
(3.2 − 2.5)V = 6.4kΩ
(3.6 − 2.5)V
(3.6 − 3.2)V = 3.6kΩ
Rbc = 10kΩ ×
(3.6 − 2.5)V
Rab = 10kΩ ×
This suggests that the position of the zero Ω
adjuster brush will be the point that divides the
variable resistor to be 6.4k Ω and 3.6k Ω.
Fig 5-7
53
The internal resistance between Point “b” and the ⊝ terminal is
Rb =
(r + Rab ) × (Rbc + R 18 )
r + Rab + Rbc + R 18
(* * * * kΩ + * * * * kΩ ) × (* * * * kΩ + * * * * kΩ )
=
* * * * kΩ + * * * * kΩ + * * * * kΩ + * * * * kΩ
= * * * * kΩ (round off to the third decimal place)
The equivalent internal resistance between the terminals, when the battery voltage is 3.2V,
is hence
R (3.2 ) = Rb + R 16 = * * * * kΩ + * * * * kΩ ≅ * * * * kΩ (round down the decimal point)
2 Ω × 1k
Since the central scale value R (internal
resistance) of the specifications is 20k Ω, the
shunt resistor R 15 is, from the equation (7)
(see Page 20), as follows :
r2 × R
Battery Internal Resistance
r2 − R
(0.3 Ω - 1 Ω)
Here, R = 20k Ω,
Fuse Resistance
(ca. 0.5 Ω)
r 1 = R 15, and r 2 = R (3.2) = 55k Ω
* * * * kΩ × * * * * kΩ
Equivalent circuit diagram of the Ohm meter
R15 =
Fig 5-8
* * * * kΩ − * * * * kΩ
≅ * * * * kΩ (round off the second decimal place)
3 Ω × 10
R = 0.2k Ω (200 Ω), r 1 = R 14, and r 2 = R (3.2) = 55k Ω
* * * * kΩ × * * * * kΩ
R14 =
= * * * * kΩ ≅ * * * * Ω (to one decimal place)
* * * * kΩ − * * * * kΩ
4Ω×1
R = 0.02k Ω (20 Ω), r 1 = R 13, and r 2 = R (3.2) = 55k Ω
* * * * kΩ × * * * * kΩ
R13 =
= * * * * kΩ ≅ * * * * Ω (to two decimal places)
* * * * kΩ − * * * * kΩ
r1 =
The actual circuit has a resistance of ca. 1.9 Ω due to the fuse and the batteries (two battery
cells). This should be subtracted from the calculated value. (The resistance is negligible for
other ranges because the value of the resistance is large.) Then,
R 13 = R 13 − 1.9Ω = * * * * Ω − 1.9Ω ≅ * * * * Ω
5-6 Battery check circuit (1.5V)
The battery check circuit connects a load resistance of 18 Ω to the battery to be checked and the
DC3V - voltmeter measures the terminal voltage. This allows examination at nearly the same
conditions as in use and hence provides the method to determine whether the battery is
functioning or has been used up.
54
Example of calculation for battery check (the case
of 1.6V)
Effective resistance between the two terminals, R 0, is
R 0 = 0.5Ω +
(R 3 + Rm ) × R 13
R 3 + Rm + R 13
( * * * * kΩ + * * * * kΩ ) × * * * * Ω
= 0.5Ω +
* * * * kΩ + * * * * kΩ + * * * * Ω
= 0.5Ω + * * * * Ω = * * * * Ω (to two decimal places)
When the voltage of the measured battery is 1.6V,
the current that flows through this circuit, I 0, is hence
Equivalent circuit diagram of battery checking
Fig 5-9
E * * * *V
I0 =
=
= * * * * mA (to one decimal place)
R 0 * * * *Ω
The current that flows through the meter circuit, im, is hence
im =
R 13
* * * *Ω
× I0 =
× * * * * mA = * * * * mA = * * * * μA
R 3 + Rm + R 13
* * * *kΩ
(to four decimal places)
The position of each graduation on the scale plate is determined for each voltage by calculation
of what percentage of Im im corresponds to.
KIT-8D Type circuit diagram
For this product, KIT - 8D, the answer values obtained from the calculation so far may differ
from the values of the resistors used in the actual circuit. This is because the product adopts
a set of resistors called ‘series resistances’. A series resistance is based on a progression of
preferred numbers that indicates what kind of number is in the set of resistances. The typical
sequences include E24 series, E96 series, etc. These progressions are also defined in the JIS
standard. Use of series resistances has the advantage in cost and availability.
55
VI Assembly of buzzer kit (optional accessory)
1. Principle
1-1 Principle of a piezoelectric buzzer
A piezoelectric buzzer element has a simple structure where a piezo - ceramic element and
a diaphragm are bonded together. When an AC voltage is applied to the piezo - ceramic
element, the element will expand and contract in the radial direction. A buzzer uses this
movement to generate sound by making the diaphragm bend repeatedly.
Fig 1
1-2 Principle of oscillator circuit
The circuit used in the buzzer circuit in the circuit diagram shown in 2. on Page 57 is an
oscillator circuit called “Astable Multivibrator”.
This circuit uses two transistors and other components such as resistors and capacitors to
output square waves (Fig 3) by periodical repetition of ON and OFF of the transistors.
This product, KIT - 8D, uses this circuit as an oscillator circuit to oscillate the buzzer. Simple
explanation of the mechanism is given below using Fig 2 and 3 : When one transistor is OFF,
base current flows through the other transistor by 10k Ω - base resistance and the transistor is
kept at ON ; at the same time, the capacitor connected to the OFF - transistor is discharging
through the resistor connected to the OFF side.
When this discharge reaches the time constant (time) determined by the capacitor and the
resistance, the OFF - transistor is switched ON and the ON - transistor is switched OFF.
Repeated operation of this gives the output of square waves.
Time
constant
circuit 2
Time
constant
circuit 1
Power
supply
(Output)
Fig 2
A stable multivibrator circuit
56
(Output)
Fig 3
Operation Waveform
2. Circuit Diagram
Buzzer circuit
Tester Ω range part
3. Parts List
Item
Piezoelectric
buzzer element
Transistors
Capacitors
Diodes
Standard
Quantity
Item
Two - terminal type,
1
Printed board
φ 20mm
2SC1815 GR
2
Lead wire
2
Lead wire
0.047µ
1S 2076A
2
Tapping screw
Fixed resistors
1/4W 1kF
2
* Adhesive
Fixed resistors
1/4W 10kF
2
Solder
Standard
Quantity
Small board for
1
soldering practice
Red 68mm
1
Black 70mm
1
2×6
1
Polyvinyl acetate
Small
emulsion adhesive amount
Remainder of
Small
assembly of the
amount
main body
※ We notify that the adhesive is not included
in the parts bag of the buzzer kit.
57
4. How to attach the piezoelectric buzzer element
1 Remove grease or dust from the surface of the panel
and the diaphragm (brass plate of the piezoelectric
buzzer element). Apply adhesive onto about three
places around the step as illustrated in Fig 1.
(Note) For convenience, use a plastic oil feeder
to apply adhesive.
2 Put the diaphragm in so that the lead wires from
the buzzer element come to the direction of the cutting
of the place to be attached. Press lightly to prevent it
from rising. The ideal method is that the adhesive
overflows and falls onto the diaphragm as shown in
Fig 2.
3 Put the lead wires of the buzzer element through the
positions indicated in Fig 3 and fix them from above
by applying adhesive on the connections. Leave for
about 16 hours to dry.
Places to apply adhesive
Fig 1
Fig 3
Adhesive
Places to apply
adhesive
Red lead
Position to fix the lead
Black lead
Fig 2
5. Assembly and wiring of the printed board
Mount each component by referring the stereoscopic wiring diagram shown below (Fig 4).
Wire the black and red leads of the small board to the large printed board of the main body
(Fig 5 and 6).
Solder the red lead (68 mm) to the
lead wire of the resistor R13.
Tapping
screw
2×6
Transistors
2SC1815
Black lead
Capacitors
Red lead
68mm
Diodes
1S 2076A
Buzzer black
lead
Buzzer red
lead
Fig 4
Fig 5
Put the black lead (70 mm)
through the position
designated in the figure
and solder it as shown.
Fig 6
58
6. Installation of the printed board
Install the completed small board to the panel.
1 Put the large printed board onto the panel
and install the small board to the position
indicated in Fig 7.
Be careful to arrange the wires so that the
wiring of the boards is not pinched between
other parts.
2 Fix the small board to the panel by the
tapping screw.
3 Put the body case and the panel together and
screw the case stopper screw to assemble
completely.
Buzzer
Buzzer black lead
Buzzer red lead
Tapping Screw
Small Board
Black lead 70mm
Meter lead red
Meter lead
black
Red lead
68mm
7. Measurement method
Warning
1. Always carry out ‘range check’ for each measurement.
2. Do not switch to other ranges during measurement.
3. Never carry out measurement when your hand is wet.
4. Circuits to which voltage is applied cannot be measured.
1) Objects to be measured
Check of conduction of wiring, etc.
2) Measurement range
Use × 1 range of the resistance measurement
3) Measurement method
1 Adjust the range selector knob to × 1 of the Ω range.
2 Short - circuit the tips of both test pins to perform zero Ω adjustment.
(The tester will generate buzzer sound.)
3 Connect the test pins to the object to be examined.
4 Check the connection by the buzzer sound and the scale plate.
The buzzer will generate sound at less than ca. 35 Ω. The sound may be difficult to catch at
levels around this value.
59
60
(Cutting line)
Parts list sheet
R1
R2
R3
R4
R5
R6
R7
R8
R9
R10
R11
R12
R13
R14
R15
R16
R17
R18
D1
D2
D3
D4
D5
D6
D7
Rated Value
4.12kF
30kJ
54.2kF
232kF
102kF
162kF
806kF
1.62MF
2.7MF
102 Ω F
10 Ω F
0.99 Ω F
18 Ω F
200 Ω G
31.6kF
48.7kF
4.87kF
39kJ
1S 2076A
1S 2076A
IN - 4004
IN - 4004
IN - 4004
IN - 4004
IN - 4004
Place to stick
Yellow
Orange
Green
Red
Brown
Brown
Grey
Brown
Red
Brown
Brown
Black
Brown
Red
Orange
Yellow
Yellow
Orange
Color code / symbol
Brown Red
Brown
Black
Black
Red
Yellow Red
Red
Orange Red
Orange
Black
Red
Orange
Blue
Red
Orange
Black
Blue
Orange
Blue
Red
Yellow
Purple
Black
Yellow
Black
Red
Black
Black
Black
Gold
White
White Silver
Grey
Black
Gold
Black
Black
Black
Brown Blue
Red
Grey
Purple Red
Grey
Purple Brown
White
Black
Red
Brown
Gold
Brown
Brown
Brown
Brown
Brown
Brown
Brown
Brown
Brown
Brown
Brown
Red
Brown
Brown
Brown
Gold
Place to stick
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MEMO
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MEMO
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MEMO
⊚ Books for reference
The following reference books are available, which explain the construction and principle of
the tester and the relevant measuring methods in an easy-to-understand manner :
“100% Effective Use of Your New Tester” published by CQ Publishing Co., Ltd.
“Effectively Using Your Digital Tester” published by Tetsugaku shuppan Co., Ltd.
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Class
Name
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