HP-760C

OPERATION MANUAL

3 1/2 DIGITAL

MULTIMETER

1． INTRODUCTION

This instrument is a compact 、battery operated、handheld 3

1/2 digital multi meter designed for use by technicians 、 servicemen 、 students 、 and hobbyists who required an instrument that is accurate、 reliable 、and always ready for use.

The Dual-slope-A/D converter uses C-MOS technology for auto-zeroing 、polarity selection and over-range indication. Full overload protection is provided. It is powered by a standard 9V transistor radio type battery .please read this manual that describes various useful message before using the multi meter.

2． Panel Layout

1）LCD Display

2）POWER Switch：Boot Up / Shut down

3）Back Light /Function switch indicator lamp key: Pressing the button turns the backlight and the function switch indicator lamp on，pressing it again turns they off.

4）CX+、CX- Input Jack

5）LX+、LX- Input Jack

6）Function switch indicator lamp

7) hFE Input Jack

8) Rotary Switch: use this switch to select functions and ranges

9) mechanical blocking

10）

Jack.

3． SPECIFICATION

system.

3.1 GENERAL CHARACTERISTICS

3.1.1 3 1/2 digit big LCD max. Indication 1999.

3.1.2 Auto-Zero & Auto-Polarity.

3.1.3 Over range: indication of “1” or “-1”.

3.1.4 Low battery indication: “ ”

3.1.5 Power supply: 9V Zinc-carbon battery.

3.1.6 Auto power off: Appox.30 minutes after power on, the meter automatically enter to power off mode. Push the “POWER” then push down it, power on again.

3.1.7 Safety standards :The meter is up to the standards of

IEC1010 Double Insulation , Pollution Degree 2 ,over voltage

Category Ⅲ.

3.1.8 Temperature for guaranteed accuracy: 23℃±5℃

3.1.9 Temperature range:

Operating :0℃ to 40 ℃ Storage : -20℃ to 60 ℃

3.1.10 Humidity range:

Operating: max 75%RH Storage: max 80%RH

3.1.11 Size: 190mm×88.5mm×27.5mm

3.1.12 Weight: Approx 320g (including battery).

3.1.13 Accessories: operation manual test leads temperature test probe packing box

1 piece

1 pair

1 pair

1 piece

3.2 MEASUREMENT SPECIFICATION

Environment :

Temperature : 23℃±5℃ relative humidity : max .75%

3.2.1 DC voltage

Range

200mV

20V

1000V

Accuracy

±(0.5% of rdg + 8digits)

±(1.5% of rdg + 8 digits)

Resolution

100μV

10mV

1V

Overload Protection : 1000V DC/700Vrms AC on other ranges.

Input impedance : 10MΩ on all ranges

3.2.2 AC voltage (Average sensing. calibreated to rms of sine wave)

Range Accuracy Resolution

2V

±(1.5% of rdg + 10 digits)

1mV

20V 10mV

700V ±(2.5% of rdg +10 digits) 1V

Frequency:2V~20V at 40Hz~400Hz; 700V at 40Hz~200Hz

Overload Protection: 1000V DC/700Vrms AC on all ranges.

Input impedance : 10 MΩ on all ranges.

3.2.3 DC Current

Range Accuracy Resolution

2mA

20mA

200mA

20A

±(0.8% of rdg +8 digits)

±(1.2% of rdg +8 digits)

±(2.0% of rdg +10 digits)

1μA

10μA

100μA

10mA

Overload Protection:0.2A/250V fuse 20A/250 fuse 20A up to 10 seconds

3.2.4 AC current (Average sensing. Calibrated to rms of sine wave )

Range

2mA

200mA

20A

Accuracy

±(1.8% of rdg + 8 digits)

±(2.0% of rdg + 8 digits)

±(3.0% of rdg + 15 digits)

Resolution

1μA

100μA

10mA

Frequency : 40~200Hz

Overload protection: 0.2A /250V fuse,20A/250V fuse 20A up to 10 seconds

3.2.5 Resistance

Range

200Ω

2kΩ

Accuracy

±(1.2% of rdg +15 digits)

Resolution

0.1Ω

1Ω

20kΩ

200kΩ

±(0.8% of rdg + 8 digits) 10Ω

100Ω

20MΩ ±(2.5% of rdg + 15 digits) 10kΩ

Overload protection:250V DC/250Vrms AC for all range.

3.2.6 Capacitance

Range

20nF

Accuracy

±(2.5% of rdg + 25 digits)

200μF

200nF

±(2.5% of rdg + 20 digits)

2μF

0~100μF ±(2.5% of rdg + 25 digits)

100~200μF ±(6.0% of rdg + 55 digits)

Overload Protection :36V DC/36Vrms AC for all range

3.2.7 Inductance

Range

20mH

200mH

Accuracy

±(2.5% of rdg + 25 digits)

Resolution

10pF

100pF

1nF

100nF

Resolution

10μH

100μH

1mH 2H

20H

3.2.8 Frequency

Range Accuracy

10mH

Resolution

200kHz ±(3.0% of rdg + 15 digits) 100Hz

Calibrated to the signal of square wave

Sensitivity: 1.0V

Overload protection: 250V DC/250Vrms AC (up to 15 seconds)

3.2.9 Temperature

Range

℃

-20～150℃

150～300℃

Accuracy

3℃+2

3.0% of rdg+2 digits

300～1000℃ 3.5% of rdg+10 digits

Resolution

1℃

1℃

1℃

K TYPE NiCr-NiSi probe

3.2.10 Transistor hFE test

Range hFE

Description

Display read approx .hFE value

(0~1000) of transistor under test

(NPN and PNP Type )

Test Condition

Bast Current approx 10 μ A

Vce approx 3V

3.2.11 Diode test and Audible Continuity Test

Range Description Test Condition

Display read approximately forward

Voltage of diode.

Forward DC current approx 1.5mA

.Reversed DC voltage

Built-in buzzer sounds if resistance is less than 80Ω. approximately 3V

Open circuit voltage approx 3V

Overload protection: 250V DC/250Vrms AC.

4. HOW TO USE THE MULTIMETER

PRELIMINARY NOTE:

1. If the battery is weak. a “ ” sign will appear on display. The battery should be replaced

2. The mark or sign“ ”near to the test lead jacks is for warning that the input voltage or current should not exceed the indicated

values. This is to prevent damage to internal circuity.

3.

The FUNCTION switch should be set to the range to be used before operation.

4.1 DC Voltage Measurement

1) Connect the BLACK test lead to the “COM” jack and the RED test lead to the “VΩ” jack

(2) set the FUNCTION switch to “V ” range to be used

(3) Connect the test leads across the source or load under measurement.

Note:

1. If the voltage range is not known beforehand. set the

FUNCTION switch to high range and work down .

2. When “1” is display, over range is being indicated and the

FUNCTION switch must be set to a higher range.

3. Don’t apply more than DC 1000V to the input, indication is possible at higher voltage but there is danger of damaging the internal circuity .

4. Use extreme caution to avoid contact with high tension circuits when measuring high voltage

4.2 AC Voltage Measurement

(1) Connect the BLACK test lead to the “COM” jack and the RED test lead to the “VΩ” jack .

(2) Set the FUNCTION switch to “V~” range to be used.

(3) Connect the test leads across the source or load under measurement.

Note:

1.

see DC voltage measurement note 1~2.

2.

Don’t apply more than 700Vrms AC to the input,indication is possible at higher voltage but there is danger of damaging the internal circuity .

3.

Use extreme caution to avoid contact with high tension circuits when measuring high voltage.

DC current Measurement

(1) Connect the BLACK test lead to the “COM” jack and the RED test lead to the “mA” jack for a maximum of 200mA. for a maximum of 20A ,move the RED test lead to “20A” .jack .

(2) Set the FUNCTION switch to “A ” range to be used.

(3) Connect the test leads in series with the load under measurement.

Note:

1. If the current range is not known beforehand .set the

FUNCTION switch to high range and work down.

2. When “1” is display, over range is being indicated and the

FUNCTION switch must be set to a higher range.

3. The maximum input current is 200mA 、20A depending upon the jack used .Excessive current will blow the fuse which must be replaced . The fuse rating should be 200mA or 20A and no more to prevent damage to the internal circuity.

4.4 AC Current Measurement

(1) Connect the BLACK test lead to the “COM” jack and the RED test lead to the “mA” jack for a maximum of 200mA.for a maximum of 20A , move the RED test lead to “20A”jack.

(2) Set the FUNCTION switch to “A～” range to be used .

(3) Connect the test leads in series with the load under measurement.

Note:

1.

If the current range is not known beforehand. .set the

FUNCTION switch to high range and work down.

2.

When “1” is display ,overrange is being indicated and the

FUNCTION switch must be set to a higher range.

3. The maximum input current is 200mA 、20A depending upon the jack used .Excessive current will blow the fuse which must be replaced . The fuse rating should be 200mA or 20A and no more to prevent damage to the internal circuity.

4.5 Resistance Measurement

(1) Connect the BLACK test lead to the “COM” jack and the RED test lead to the “VΩ” jack .

(2) Set the FUNCTION switch to “Ω ” range to be used

(3) Connect the test leads across the resistance under measurement.

Note:

1. If the resistance value being measured exceeds the maximum value of the range selected, an over-range indication will be displayed (“1”). Select a higher range .For resistance of approximately 1 Megohm and alove . the meter may take a few seconds to stabilize . This is normal for high resistance readings.

2. When the input is not connected , i. e at open circuit .the sign

“1” will be displayed for the overrange condition . when checking in-circuit resistance, be sure the circuit under test has all power removed and that all capacitors are fully discharged .

4.6 Capacitance Measurement

(1) Set the FUNCTION switch to “C” to be used and the “LC” button to be pushed down.

(2) Insert the capacitor under measurement into the two jacks

“LCx-” and “LCx+” on the front panel.

Note:

1.

Capacitors should be discharged before being inserted into the test-jacks.

2.

When testing large capacitance, note that there will be a certain time lag before the final indication.

3.

Do not connect an external voltage or charged capacitor

(especially larger capacitors ) to measuring terminals.

4.7 Inductance Measurement

(1) Set the FUNCTION switch to “L” to be used and the “LC” button to be pushed down.

(2) Insert the inductor under measurement into the two jacks“LCx-” “LCx+” on the front panel.

4.8 Frequency Measurement

(1) Connect the BLACK test lead to the “COM” jack and the RED test lead to the “VΩ” jack .

(2) Set the FUNCTION switch to “200KHz” range to be used.

(3) Connect the test leads to the point under measurement.

4.9 Temperature Measurement

(1) Connect the BLACK test lead of the sensor to “T-” jack, the

RED test to “T+” jack.

(2) Set the FUNCTION switch to “ ℃”

Put the sensor probe into the temperature field under measurement.

A. The temperature function shows the random number at ordinary times, must insert the thermocouple in temperature test hole while examining temperature. In order to guarantee the accuracy of the measurement, need to close Light switch while measuring temperature.;

A. This meter inclosure WRNM-010 type contact thermocouple limit temperature is 250 ℃ (300 ℃ shortly ) ;

B. Please don't change the thermocouple at will , otherwise we can't guarantee to measure accuracy ;

C. Please don’t importing the voltage in the temperature function.

E. Please use special probe for test high temperature.

4.10 Diode Measurement and audible continuity test

(1) Connect the BLACK test lead to “COM” jack and the RED test lead to the “VΩ” jack..

(2) Set the FUNCTION switch to the “ ” range and connect the test leads across the diode under measurement, display shows the approx. forward voltage of this diode.

(3) Connect the test leads to two point of circuit, if the resistance is lower than approx. 80Ω,the buzzer sounds.

4.10 Transistor hFE Test

(1) Set the FUNCTION switch the “hFE” range.

(2) Determine whether the transistor is NPN or PNP and locate the Emitter. Base and collector leads. Insert the leads into the proper holes in the socker on the front pane.

(3) The display will read the approximated hFE value at the test condition Base current 10uA , Vce3V.

4.12 back light

Press button "LIGHT" backlight illume, Again press once backlight breath go out.

5..MAINTENANCE

(1) The multi meter is a precision electronic device Do not tamper with the circuity . to avoid damage :

A : Never connect more than 1000V DC or 750Vrms AC.

B : Never connect a source of voltage under the condition of resistance measurement .

C : Never operate the meter unless the battery cover is in place and fully closed .

D : Battery and / or fuse replacement should be done after the test leads have been disconnected and POWER IS OFF .

(2) turn off the power if the meter is not in use , removed the battery if the meter will be free for long period .

(3) If a sign of “ ” appear on the display, open the compartment cover, remove the spent battery and replace it with a battery of the same type. fuse replacement fellow the same the same steps .

(4) Contact with the maintenance service center of our company if you have trouble.

(5)

time.

Please take out the battery when not using for a long