ATP Instrumentation DT-931 User manual

OPERATING INSTRUCTION
AUTORANGINGMULTIMETER
COM
MAX
10A
15 min.
every
MAX
Ω
V
C
F

2
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
on the front of the meter.

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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.
This WARNING symbol indicates a potentially
hazardous situation, which if not avoided, could
result in death or serious injury.
This CAUTION symbol indicates a potentially
hazardous situation, which if not avoided, may
result damage to the product.
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.
This symbol adjacent to one or more terminals
identifies them as being associated with ranges that
may, in normal use, be subjected to particularly
Input Limits
Function
Maximum Input
V DC or V AC
1000VDC/AC
A DC/AC
10A DC/AC (30
seconds max every
15 minutes)
Frequency,
Resistance,
Capacitance, Duty
Cycle, Diode test,
Continuity
600V DC/AC
Temperature
600V DC/AC
WARNING
CAUTION
MAX
500V

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hazardous voltages. For maximum safety, the meter
and its test leads should not be handled when these
terminals are energized.
CONTROLS AND JACKS
COM
MAX
10A
15 min.
every
MAX
Ω
V
C
F
8
9
5
1
7
6
3
4
2
1. 6000 count Liquid Crystal Display with symbolic signs

5
2. Function switch
3. 10A (positive) input jack for 10A DC or AC measurements
4. COM (negative) input jack
5. Positive input jack
6. HOLD & Backlight pushbutton
7. Max/Min pushbutton
8. Range/ .Diode pushbutton
9. Hz/Duty pushbutton
SYMBOLS AND ANNUNCIATORS
Continuity
BAT Low Battery
Diode
HOLD Data Hold
AUTO AutoRanging
AC Alternating Current or Voltage
DC Direct Current or Voltage
SPECIFICATIONS
The instrument complies with: EN61010-1.
Insulation: Class2, Double insulation.

6
Overvoltage category: CATIII 600V, CATII 1000V.
Display: 6000 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.
Operating environment: 0 oC to 50 oC (32
o
F to 122
o
F) at <
70 % relative humidity.
Storage temperature: -20 oC to 60 oC (-4
o
F to 140
o
F) 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
o
F to 83
o
F), less than
70 % RH
DC Voltage
Range
Resolution
Accuracy
600.0mV
0.1mV
+0.5% of rdg + 2 dgts

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6.000V
1mV
+1.2% of rdg + 2 dgts
60.00V
10mV
600.0V
100mV
1000V
1V
+1.5% of rdg + 2 dgts
Input Impedance: 7.8M.
Maximum Input: 1000V dc or 1000V ac rms.
AC Voltage
Range
Resolution
Accuracy
6.000V
1mV
+1.2% of rdg + 3 dgts
60.00V
10mV
+1.5% of rdg + 3 dgts
600.0V
100mV
1000V
1V
+2.0% of rdg + 4 dgts
Input Impedance: 7.8M.
Frequency Range:50 to 60Hz
Maximum Input: 1000V dc or 1000V ac rms.
DC Current
Range
Resolution
Accuracy
6A
1mA
+2.5% of rdg + 5 dgts
10A
10mA
Overload Protection: 10A / 250V Fuse.
Maximum Input: 10A dc or ac rms on 10A DC range.
AC Current
Range
Resolution
Accuracy
6A
1mA
+3.0% of rdg + 5 dgts
10A
10mA
Overload Protection: 10A / 250V Fuse.
Frequency Range: 50 to 60 Hz

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Maximum Input: 10A dc or ac rms on 10AAC range.
Resistance
Range
Resolution
Accuracy
600.0
0.1
+1.2% of rdg + 4 dgts
6.000k
1
+1.0% of rdg + 2 dgts
60.00k
10
+1.2% of rdg + 2 dgts
600.0k
100
6.000M
1k
+2.0% of rdg + 2 dgts
60.00M
10k
+5.0% of rdg + 10 dgts
Maximum Input: 600V dc or 600V ac rms.
Capacitance (Auto-ranging)
Range
Resolution
Accuracy
40.00nF
10pF
+5.0% of rdg + 50 dgts
400.0nF
0.1nF
+3.0% of rdg + 5 dgts
4.000uF
1nF
40.00uF
10nF
400.0uF
0.1uF
+5.0% of rdg + 5 dgts
4000uF
1uF
+5.0% of rdg + 5 dgts
Maximum Input: 600V dc or 600V ac rms.
Frequency (Auto-ranging)
Range
Resolution
Accuracy
9.999Hz
0.001Hz
+1.5% of rdg + 5 dgts
99.99Hz
0.01Hz
999.9Hz
0.1Hz
+1.2% of rdg + 3 dgts
9.999kHz
1Hz
99.99kHz
10Hz

9
999.9kHz
100Hz
10MHz
1kHz
+1.5% of rdg + 4 dgts
Sensitivity: >0.5V RMS while ≤1MHz ;
Sensitivity: >3V RMS while >1MHz ;
Maximum Input: 600V dc or 600V ac rms.
Duty Cycle
Range
Resolution
Accuracy
0.1%~99.9%
0.1%
+1.2% of rdg + 2 dgts
Pulse width: >100us, <100ms;
Frequency width: 5Hz –150kHz
Sensitivity: >0.5V RMS
Maximum Input: 600V dc or 600V ac rms.
Temperature
Range
Resolution
Accuracy
-20
o
C~+760
o
C
1
o
C
+3% of rdg
+5
o
C/9
o
F
-4
o
F~+1400
o
F
1
o
F
Sensor: Type K Thermocouple
Overload protection: 600V dc or ac rms..
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: 600V dc or ac rms.

10
Audible continuity
Audible threshold: Less than 100 Test current: <0.3mA
Overload protection: 600V 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
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.
AUTORANGING/MANUAL RANGE SELECTION
When the meter is first turned on, it automatically goes into

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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 key. The “AUTO” display indicator will turn off
or select diode /beeper, AC/DC Clamp
2. Press the RANGE key to step through the available ranges until you
select the range you want.
3. To exit the Manual Ranging mode and return to Autoranging, press
and hold the RANGE key for 2 seconds.
Note: Manual ranging does not apply for the Frequency functions.
MAX/MIN
Note: When using the MAX/MIN function in Autoranging mode, the
meter will “lock” into the range that is displayed on the LCD
when MAX/MIN is activated. If a MAX/Min reading exceeds
that range, an “OL” will be displayed. Select the desired range
BEFORE entering MAX/MIN mode.
1. Press the MAX/MIN key to activate the MAX/MIN recording mode.
The display icon "MAX" will appear. The meter will display and hold
the maximum reading and will update only when a new “max”
occurs.

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2. Press the MAX/MIN key again and the display icon "MIN" will
appear. The meter will display and hold the minimum reading and
will update only when a new “min” occurs.
3. To exit MAX/MIN mode press and hold the MAX/MIN key for 2
seconds
DISPLAY BACKLIGHT
Press and hold the HOLD key for >1 second to turn on or off the
display backlight function. The backlight will automatically turn off
after 10 seconds.
HOLD
The hold function freezes the reading in the display. Press the HOLD
key momentarily to activate or to exit the HOLD function.
Hz/duty
1. Switch to Hz/Duty range.
2. Press the Hz/Duty button to show the reading in the display
and the "Hz/Duty" indicator will appear on the display.
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.

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1. Set the function switch to the V DC 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. Be sure to observe
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)

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jack and the red test lead banana plug into the positive (V)
jack.
3. Touch the test probe tips to the circuit under test.
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 DC current measurements, set the function switch to the DC 10A
position and insert the red test lead banana plug into the 10A jack.
3. Remove power from the circuit under test, then open up the circuit at
the point where you wish to measure current.
4. 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.
5. Apply power to the circuit.
6. 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

15
any circuit whose voltage exceeds 250VAC.
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 ACcurrent measurements , set the function switch to the AC 10A
position and insert the red test lead banana plug into the 10A jack.
3. Remove power from the circuit under test, then open up the circuit at
the point where you wish to measure current.
4. 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.
5. Apply power to the circuit.
6. Read the current in the display. The display will indicate the
proper decimal point, value and symbol.

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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.
5. If the resistance is less than approximately 100, the audible signal

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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.

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FREQUENCY MEASUREMENT
1. Set the function switch to the FREQ position.
2. Insert the black test lead banana plug into the negative (-) jack (COM)
and the red test lead banana plug into the positive (+) jack (F).
3. Touch the test probe tips to the circuit under test.
4. Read the frequency in the display. The digital reading will indicate the
proper decimal point, symbols (Hz, kHz) and value.
CAPACITANCE MEASUREMENTS
WARNING: To avoid electric shock, disconnect power to the unit
under test and discharge all capacitors before taking any capacitance
measurements. Remove the batteries and unplug the line cords.
1. Set the function switch to the CAP position. (“nF” and a small value
will appear in the display).
2. Insert the black test lead banana plug into the negative (-) jack (COM)
and the red test lead banana plug into the positive (+) jack (CAP).
Touch the test leads to the capacitor to be tested. The display will indicate
the proper decimal point, value and symbol

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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 oF, set the function switch to the
oF range. If you wish to measure temperature in oC, set the function
switch to the oC range.
2. Insert the type K thermocouple probe black test lead banana
plug into the negative COM jack and the red test lead banana
plug into the positive Temp jack..
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.
REPLACING THE BATTERY
WARNING: To avoid electric shock, disconnect the test leads from any
source of voltage before removing the battery door.

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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.
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.