ATP Instrumentation DM-921 Operating
The ATP Instrumentation DM-921 is a powerful and versatile autoranging multimeter that is perfect for a wide variety of electrical measurements. It features a large 2000-count LCD display, a rugged construction, and a variety of measurement functions, including AC/DC voltage, AC/DC current, resistance, temperature, continuity, and diode testing. The DM-921 also has a number of advanced features, such as auto-ranging, data hold, and max hold. The DM-921 is a great choice for professional electricians, engineers, and hobbyists alike.
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OPERATING INSTRUCTION
AUTORANGING MULTIMETER
AUTO
DC
AC
Mode Range
MAX
C F
C F
V
V
Ω
μ
10A
MAX
15 min.
COM
V ¦¸
μ
SAFETY INFORMATION
The following safety information must be observed to insure maximum personal safety during the operation at this meter:
Do not use the meter if the meter or test leads look damaged, or if you suspect that the meter is not operating properly.
Never ground yourself when taking electrical measurements.
Do not touch exposed metal pipes, outlets, fixtures, etc., which might be at ground potential. Keep your body isolated from ground by using dry clothing, rubber shoes, rubber mats, or any approved insulating material.
Turn off power to the circuit under test before cutting, unsoldering, or breaking the circuit. Small amounts of current can be dangerous.
Use caution when working above 60V dc or 30V ac rms. such voltages pose a shock hazard.
When using the probes, keep your fingers behind the finger guards on the probes.
Measuring voltage which exceeds the limits of the multimeter may damage the meter and expose the operator to a shock hazard. Always recognize the meter voltage limits as stated
1
on the front of the meter.
Never apply voltage or current to the meter that exceeds the specified maximum:
SAFETY SYMBOLS
This symbol adjacent to another symbol, terminal or operating device indicates that the operator must refer to an explanation in the Operating Instructions to avoid personal injury or damage to the meter.
WARNING This WARNING symbol indicates a potentially hazardous situation, which if not avoided, could result in death or serious injury.
CAUTION This CAUTION symbol indicates a potentially hazardous situation, which if not avoided, may result damage to the product.
MAX
500V
This symbol advises the user that the terminal(s) so marked must not be connected to a circuit point at which the voltage with respect to earth ground exceeds (in this case) 500 VAC or VDC.
2
This symbol adjacent to one or more terminals identifies them as being associated with ranges that may, in normal use, be subjected to particularly hazardous voltages. For maximum safety, the meter and its test leads should not be handled when these terminals are energized.
Function
V DC or V AC mA DC/AC
A DC/AC
Resistance, Diode test,
Continuity
Temperature
Input Limits
Maximum Input
CATII-1000V DC /AC
CATIII-600V DC /AC
200mA DC/AC
10A DC/AC (30 seconds max every 15 minutes)
500V DC/AC
CONTROLS AND JACKS
1.
2000 count Liquid Crystal Display with symbolic signs
2.
3.
Function switch
Positive input jack
3
7.
8.
9.
4.
5.
6.
COM (negative) input jack
10A (positive) input jack for 10A DC or AC measurements
Mode pushbutton: selection Continuity/Diode, AC/DC,
Temperature(C/F)
Range pushbutton
Data Hold pushbutton
MAX. Hold pushbutton
1
7
6
2
5
4
AUTO
DC
AC
MAX
Mode Range
C F
V
V
Ω
C F
10A
MAX every
15 min.
COM
V ¦¸
μ
μ
3
8
9
4
SYMBOLS AND ANNUNCIATORS
Continuity
BAT Low Battery
Diode
DATA HOLD Data Hold
AUTO AutoRanging
AC
DC
Alternating Current or Voltage
Direct Current or Voltage
SPECIFICATIONS
The instrument complies with: EN61010-1.
Insulation: Class2, Double insulation.
Overvoltage category: CATIII 600V, CATII 1000V.
Display: 2000 counts LCD display with function indication.
Polarity: Automatic, (-) negative polarity indication.
Overrange: “OL” mark indication.
Low battery indication: The “BAT” is displayed when the battery voltage drops below the operating level.
Measurement rate: 2 times per second, nominal.
Auto power off: Meter automatically shuts down after approx. 15 minutes of inactivity.
5
Operating environment: 0 oC to 50 oC (32 oF to 122 oF) at <
70 % relative humidity.
Storage temperature: -20 oC to 60 oC (-4 oF to 140 oF) at < 80 % relative humidity.
For inside use, max height: 2000m
Pollution degree: 2
Power: One 9V battery , NEDA 1604, IEC 6F22.
Dimensions: 150 (H) x 70 (W) x 48 (D) mm
Weight: Approx.: 255g.
Accuracy is given at 18 oC to 28 oC (65 oF to 83 oF), less than
70 % RH
DC Voltage (Auto-ranging)
Range
200.0mV
2.000V
20.00V
200.0V
600V(CATIII)
1000V(CATII)
Resolution Accuracy
0.1mV
1mV
10mV
100mV
1V
+0.5% of rdg + 2 dgts
+1.2% of rdg + 2 dgts
+1.5% of rdg + 2 dgts
+1.5% of rdg + 4 dgts
Input Impedance: 10M
.
Maximum Input: 600V dc/ac rms.(CATIII)
Maximum Input: 1000V dc/ac rms.(CATII)
6
AC Voltage (Auto-ranging except 200mV)
Range
200.0mV
2.000V
20.00V
200.0V
600V(CATIII)
Resolution Accuracy
0.1mV
1mV
10mV
100mV
1V
+1.5%of rdg + 30 dgts
+1.2% of rdg + 3 dgts
+1.5% of rdg + 3 dgts
+2.0% of rdg + 4 dgts
1000V(CATII)
Input Impedance: 10M
.
+2.0% of rdg + 8 dgts
Frequency Range:50 to 60Hz
Maximum Input: 600V dc/ac rms.(CATIII)
Maximum Input: 1000V dc/ac rms.(CATII)
DC Current (Auto-ranging for uA and mA)
Range
200.0uA
2000uA
20.00mA
Resolution Accuracy
0.1uA +1.0% of rdg + 3 dgts
1uA
10uA +1.5% of rdg + 3 dgts
200.0mA 100uA
10A 10mA +2.5% of rdg + 5 dgts
Overload Protection: 0.2A / 250V and 10A / 250V Fuse.
Maximum Input: 200mA dc or 200mA ac rms on uA / mA ranges,
10A dc or ac rms on 10A range.
AC Current (Auto-ranging for uA and mA)
7
Range Resolution Accuracy
200.0uA 0.1uA
2000uA 1uA
+1.5% of rdg + 5 dgts
+1.8% of rdg + 5 dgts 20.00mA 10uA
200.0mA 100uA
10A 10mA +3.0% of rdg + 7 dgts
Overload Protection: 0.2A / 250V and 10A / 250V Fuse.
Frequency Range: 50 to 60 Hz
Maximum Input: 200mA dc or 200mA ac rms on uA / mA ranges,
10A dc or ac rms on 10A range.
Clamp-on Adaptors DC Current
Range Resolution Accuracy
200A 0.1A
2000A 1A
+1.0% of rdg +3dgts
(meter only, Clamp-on
Adaptor accuracy not included)
Sensor: Clamp-on Adaptor (Note: not provide)
200A Range Input Sensitivity: 1mV/A
2000A Range Input Sensitivity: 1mV/A
Overload protection: 500V dc or ac rms..
Clamp – on Adaptor AC Current
Range Resolution Accuracy
8
200A 0.1A
2000A 1A
+1.5% of rdg +3dgts
(meter only, Clamp-on
Adaptor accuracy not included)
Sensor: Clamp-on Adaptor (Note: not provide)
200A Range Input Sensitivity: 1mV/A
2000A Range Input Sensitivity: 1mV/A
Frequency Range: 50 to 60 Hz
Overload protection: 500V dc or ac rms..
Resistance (Auto-ranging)
Range Resolution
200.0
0.1
2.000k
1
20.00k
10
200.0k
100
2.000M
1k
20.00M
10k
Accuracy
+1.2% of rdg + 4 dgts
+1.0% of rdg + 2 dgts
+1.2% of rdg + 2 dgts
+2.0% of rdg + 3 dgts
Input Protection: 500V dc or 500V ac rms.
Temperature
Range
-50oC~+1000oC
Resolution Accuracy
1 oC
+3% of rdg +5dgts
-58oF~+1832 oF 1oF
+3% of rdg +8dgts
Sensor: Type K Thermocouple
Overload protection: 500V dc or ac rms..
9
Diode Test
Test current Resolution Accuracy
0.3mA typical
1 mV +10% of rdg + 5 dgts
Open circuit voltage: 1.5V dc typical
Overload protection: 500V dc or ac rms.
Audible continuity
Audible threshold: Less than100
Test current: <0.3mA
Overload protection: 500V dc or ac rms.
OPERATION
WARNING : Risk of electrocution. High-voltage circuits, both AC and DC, are very dangerous and should be measured with great care.
1.
ALWAYS turn the function switch to the OFF position when the meter is not in use. This meter has Auto OFF that automatically shuts the meter OFF if 15 minutes elapse between uses.
2.
If “OL” appears in the display during a measurement, the
10
value exceeds the range you have selected. Change to a higher range.
NOTE : On some low AC and DC voltage ranges, with the test leads not connected to a device, the display may show a random, changing reading.
This is normal and is caused by the high-input sensitivity. The reading will stabilize and give a proper measurement when connected to a circuit.
MODE BUTTON
To select Diode/Continuity or DC/AC voltage, current,Temperature(C/F)
RANGE BUTTON
When the meter is first turned on, it automatically goes into AutoRanging.
This automatically selects the best range for the measurements being made and is generally the best mode for most measurements. For measurement situations requiring that a range be manually selected, perform the following:
1.
Press the RANGE button. The “AUTO” display indicator will turn off.
2. Press the RANGE button to step through the available ranges until you select the range you want.
3.
Press and hold the RANGE button for 2 seconds to exit the ManualRanging mode and return to AutoRanging.
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DATA HOLD BUTTON
The Data Hold function allows the meter to "freeze" a measurement for later reference.
1.
Press the DATA HOLD button to “freeze” the reading on the indicator. The indicator “HOLD” will be appear in the display.
2.
Press the DATA HOLD button to return to normal operation.
MAX HOLD BUTTON
The max. Hold position is used to measure the maximum value .
The maximum measured value is up dated continuously. Press once again the button, will release the hold and allow a further measurement.
DC VOLTAGE MEASUREMENTS
CAUTION: Do not measure DC voltages if a motor on the circuit is being switched ON or OFF. Large voltage surges may occur that can damage the meter.
1.
Set the function switch to the V DC position (“mV” will appear in the display).
2.
Insert the black test lead banana plug into the negative (COM) jack and the red test lead banana plug into the positive (V) jack.
3.
Touch the test probe tips to the circuit under test. Be sure to observe
12
the correct polarity (red lead to positive, black lead to negative).
4.
Read the voltage in the display. The display will indicate the proper decimal point and value. If the polarity is reversed, the display will show (-) minus before the value.
AC VOLTAGE MEASUREMENTS
WARNING: Risk of Electrocution. The probe tips may not be long enough to contact the live parts inside some 240V outlets for appliances because the contacts are recessed deep in the outlets. As a result, the reading may show 0 volts when the outlet actually has voltage on it. Make sure the probe tips are touching the metal contacts inside the outlet before assuming that no voltage is present.
CAUTION: Do not measure AC voltages if a motor on the circuit is being switched ON or OFF. Large voltage surges may occur that can damage the meter.
1.
Set the function switch to the V AC position.
2.
Insert the black test lead banana plug into the negative (COM) jack and the red test lead banana plug into the positive (V) jack.
3.
Touch the test probe tips to the circuit under test.
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4.
Read the voltage in the display. The display will indicate the proper decimal point, value and symbol (AC, V, etc.).
DC CURRENT MEASUREMENTS
CAUTION: Do not make current measurements on the 10A scale for longer than 30 seconds. Exceeding 30 seconds may cause damage to the meter and/or the test leads.
1.
Insert the black test lead banana plug into the negative (COM) jack.
2.
For current measurements up to 2000
A DC, set the function switch to the
A position and insert the red test lead banana plug into the (
A) jack.
3.
For current measurements up to 200mA DC, set the function switch to the mA range and insert the red test lead banana plug into the (mA) jack.
4.
For current measurements up to 10A DC, set the function switch to the
A position and insert the red test lead banana plug into the 10A jack.
5.
Press the AC/DC button until “DC” appears in the display.
6.
Remove power from the circuit under test, then open up the circuit at the point where you wish to measure current.
7.
Touch the black test probe tip to the negative side of the circuit. Touch the red test probe tip to the positive side of the circuit.
14
8.
Apply power to the circuit.
9. Read the current in the display. The display will indicate the proper decimal point, value and symbol.
AC CURRENT MEASUREMENTS
WARNING: To avoid electric shock, do not measure AC current on any circuit whose voltage exceeds 250V AC.
CAUTION: Do not make current measurements on the 10A scale for longer than 30 seconds. Exceeding 30 seconds may cause damage to the meter and/or the test leads.
1.
Insert the black test lead banana plug into the negative (COM) jack.
2.
For current measurements up to 2000
A AC, set the function switch to the
A position and insert the red test lead banana plug into the (
A) jack.
3.
For current measurements up to 200mA AC, set the function switch to the mA range and insert the red test lead banana plug into the (mA) jack.
4.
For current measurements up to 10A AC, set the function switch to the
A position and insert the red test lead banana plug into the 10A jack.
5.
Press the AC/DC button until “AC” appears in the display.
6.
Remove power from the circuit under test, then open up the circuit at
15
the point where you wish to measure current.
7.
Touch the black test probe tip to the negative side of the circuit. And touch the red test probe tip to the positive side of the circuit.
8.
Apply power to the circuit.
9.
Read the current in the display. The display will indicate the proper decimal point, value and symbol.
CLAMP–ON ADAPTOR
MEASUREMENTS
AC/DC CURRENT
1.
Set the function switch to the A DC/AC (clamp–on adaptor) position
2.
Insert the clamp–on adaptor black test lead banana plug into the negative (COM) jack and the red test lead banana plug into the positive (V) jack.
3.
Press the MODE button until “AC/DC” appears in the display.
4.
Press the trigger to open jaw. Fully enclose one conductor to be measured.
5.
Read the AC/DC current in the display.
NOTE: The output analog signal Sensitivity of The AC/DC CLAMP–ON
ADAPTOR is 1mV/A
16
RESISTANCE MEASUREMENTS
WARNING: To avoid electric shock, disconnect power to the unit under test and discharge all capacitors before taking any resistance measurements. Remove the batteries and unplug the line cords.
1.
Set the function switch to the
position.
2.
Insert the black test lead banana plug into the negative (COM) jack and the red test lead banana plug into the positive
jack.
3.
Touch the test probe tips across the circuit or part under test. It is best to disconnect one side of the part under test so the rest of the circuit will not interfere with the resistance reading.
4.
Read the resistance in the display. The display will indicate the proper decimal point, value and symbol.
CONTINUITY CHECK
WARNING: To avoid electric shock, never measure continuity on circuits or wires that have voltage on them.
1.
Set the function switch to the position.
2.
Insert the black lead banana plug into the negative (-) jack (COM) and the red test lead banana plug into the positive (+) jack (
).
3.
Press the button until the symbol appears in the display.
4.
Touch the test probe tips to the circuit or wire you wish to check.
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5.
If the resistance is less than approximately 30
, the audible signal will sound. The display will also show the actual resistance.
DIODE TEST
WARNING: To avoid electric shock, do not test any diode that has voltage on it.
1. Set the function switch to position.
2. Press the button until the symbol appears in the display.
3. Insert the black test lead banana plug into the negative (-) jack (COM) and the red test lead banana plug into the positive (+) jack (
).
4.
Touch the test probe tips to the diode or semiconductor junction you wish to test. Note the meter reading
5. Reverse the probe polarity by switching probe position. Note this reading.
6. The diode or junction can be evaluated as follows:
A. If one reading shows a value and the other reading shows OL, the diode is good.
B. If both readings show OL, the device is open.
C. If both readings are very small or 0, the device is shorted.
NOTE: The value indicated in the display during the diode check is the forward voltage.
18
TEMPERATURE MEASUREMENTS
WARNING: To avoid electric shock, disconnect both test probes from any source of voltage before making a temperature measurement.
1. If you wish to measure temperature in o
F, set the function switch to the o
F range. If you wish to measure temperature in o
C, set the function switch to the o
C range.
2 Insert the black test lead banana plug into the negative (COM) jack and the red test lead banana plug into the positive (V) jack, making sure to observe the correct polarity.
3.
Touch the Temperature Probe head to the part whose temperature you wish to measure. Keep the probe touching the part under test until the reading stabilizes (about 30 seconds).
4.
Read the temperature in the display. The digital reading will indicate the proper decimal point and value.
WARNING: To avoid electric shock, be sure the thermocouple has been removed before changing to another measurement function.
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REPLACING THE BATTERY
WARNING : To avoid electric shock, disconnect the test leads from any source of voltage before removing the battery door.
1.
When the batteries become exhausted or drop below the operating voltage, “BAT” will appear in the right-hand side of the LCD display.
The battery should be replaced.
2.
Follow instructions for installing battery. See the Battery Installation section of this manual.
3. Dispose of the old battery properly.
WARNING: To avoid electric shock, do not operate your meter until the battery door is in place and fastened securely.
BATTERY INSTALLATION
WARNING : To avoid electric shock, disconnect the test leads from any source of voltage before removing the battery door.
1.
Disconnect the test leads from the meter.
2.
Open the battery door by loosening the screw using a Phillips head screwdriver.
3.
Insert the battery into battery holder, observing the correct polarity.
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4.
Put the battery door back in place. Secure with the two screws.
WARNING: To avoid electric shock, do not operate the meter until the battery door is in place and fastened securely.
NOTE : If your meter does not work properly, check the fuses and battery to make sure that they are still good and that they are properly inserted.
REPLACING THE FUSES
WARNING : To avoid electric shock, disconnect the test leads from any source of voltage before removing the fuse door.
1. Disconnect the test leads from the meter and any item under test.
2. Open the fuse door by loosening the screw on the door using a Phillips head screwdriver.
3. Remove the old fuse from its holder by gently pulling it out.
3.
Install the new fuse into the holder.
4.
Always use a fuse of the proper size and value (0.2A/250V fast blow for the 200mA range, 10A/250V fast blow for the 10A range).
5.
Put the fuse door back in place. Insert the screw and tighten it securely.
WARNING : To avoid electric shock, do not operate your meter until the fuse door is in place and fastened securely.
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Key features
- 2000-count LCD display
- Autoranging
- Data hold and max hold
- Rugged construction
- Variety of measurement functions
- CAT III 600V safety rating
- Low battery indicator
- Auto power off