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6

Operating Instructions 

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. 

2. If “

OL

” appears in the display during a measurement, the value exceeds the range you have 

selected. Change to a higher range.  

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 green 

VDC

 position.  

2. Insert the black test lead banana plug into the negative 

COM

 jack. 

Insert the red test lead banana plug into the positive 

V

 jack. 

3. 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. 

4. Read the voltage in the display.  

 
 
 
 
 
 
AC VOLTAGE (FREQUENCY, DUTY CYCLE) 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 green 

VAC/Hz/%

 position. 

2. 

 Insert the black test lead banana plug into the negative 

COM

 jack. 

  Insert red test lead banana plug into the positive 

V

 jack. 

3. 

 Touch the black test probe tip to the neutral side of the circuit.  

  Touch the red test probe tip to the “hot” side of the circuit. 

4. Read the voltage in the display. 
5. Press the 

HZ/%

 button to indicate “

Hz

”. 

6. Read the frequency in the display. 
7. Press the 

Hz/%

 button again to indicate “

%

”. 

8. Read the % of duty cycle in the display. 
 
 
 
 

Summary of Contents for DT-985

Page 1: ...DT 985 TRMS MULTIMETER ...

Page 2: ... 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 This symbol indicates that a device is protected throughout by double insulation or reinforced insulation PER IEC1010 OVERVOLTAGE INSTALLATION CATEGORY OVERVOLTAGE CATEGORY I Equipment of OVERVOLTAGE CATEGORY I is eq...

Page 3: ... EXTREME CAUTION when working with high voltages 3 DO NOT measure voltage if the voltage on the COM input jack exceeds 1000V above earth ground 4 NEVER connect the meter leads across a voltage source while the function switch is in the current resistance or diode mode Doing so can damage the meter 5 ALWAYS discharge filter capacitors in power supplies and disconnect the power when making resistanc...

Page 4: ... MIN button 3 RANGE button 4 Mode button 5 Function switch 6 mA µA and 10A input jacks 7 COM input jack 8 Positive input jack 9 HOLD and Backlight button 10 Hz and button 11 RELATIVE button 12 Battery Cover Note Tilt stand and battery compartment are on rear of unit ...

Page 5: ...cro 10 6 amps cap m milli 10 3 volts amps A Amps k kilo 103 ohms F Farads capacitance M mega 106 ohms Ohms Hz Hertz frequency V Volts Percent duty ratio REL Relative AC Alternating current AUTO Autoranging DC Direct current HOLD Display hold ºF Degrees Fahrenheit ºC Degrees Centigrade MAX Maximum MIN Minimum ...

Page 6: ... AC VOLTAGE FREQUENCY DUTY CYCLE 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 ...

Page 7: ... FREQUENCY DUTY CYCLE MEASUREMENTS CAUTION Do not make 10A current measurements 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 6000µA AC set the function switch to the yellow µA position and insert the red test lead banana plug into the µA mA jac...

Page 8: ... circuits or wires that have voltage on them 1 Set the function switch to the green Ω CAP position 2 Insert the black lead banana plug into the negative COM jack Insert the red test lead banana plug into the positive jack 3 Press the MODE button to indicate and Ω on 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 50 th...

Page 9: ... the batteries and unplug the line cords 1 Set the rotary function switch to the green Ω CAP position 2 Insert the black test lead banana plug into the negative COM jack Insert the red test lead banana plug into the positive V jack 3 Press the MODE button to indicate nF on the display 4 Touch the test leads to the capacitor to be tested 5 The test may take up to 3 minutes or more for large capacit...

Page 10: ...he 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 RELATIVE MODE The relative measurement feature allows you to make measurements relative to a stored reference value A reference voltage current etc can be stored and measurements made in comparison to that value The displayed value is the...

Page 11: ...TALLATION WARNING To avoid electric shock disconnect the test leads from any source of voltage before removing the battery cover 1 Turn power off and disconnect the test leads from the meter 2 Open the rear battery cover by removing the screw using a Phillips head screwdriver 3 Insert the battery into battery holder observing the correct polarity 4 Put the battery cover back in place Secure with t...

Page 12: ...rom 5 of range to 100 of range DC Current 600 A 0 1 A 1 0 reading 3 digits 6000 A 1 A 60mA 0 01mA 600mA 0 1mA 6A 0 001A 1 5 reading 3 digits 10A 0 01A 10A 30 sec max with reduced accuracy AC Current 45Hz to 60Hz 600 A 0 1 A 1 5 reading 3 digits 6000 A 1 A 60mA 0 01mA 600mA 0 1mA 6A 0 001A 2 0 reading 5 digits 10A 0 01A 10A 30 sec max with reduced accuracy All AC voltage ranges are specified from 5...

Page 13: ... 99Hz 0 01Hz 999 9Hz 0 1Hz 9 999kHz 0 001kHz 99 99kHz 0 01kHz 999 9kHz 0 1kHz 9 999MHz 0 001MHz 10MHz 0 01MHz Frequency electrical 10 00 10KHz 0 01Hz 1 2 reading Sensitivity 15Vrms Duty Cycle 0 1 to 99 9 0 1 1 2 reading 2 digits Pulse width 100µs 100ms Frequency 5Hz to 10kHz Temp type K 4 to 1400 F 1 F 3 0 reading 5 C 9 F digits probe accuracy not included 20 to 760 C 1 C Note Accuracy specificati...

Page 14: ... times per second nominal Low Battery Indication is displayed if battery voltage drops below operating voltage Battery 1 5VAAA 4 battery Fuses mA µA ranges 0 8A 1000V ceramic fast blow A range 10A 1000V ceramic fast blow Operating Temperature 41 F to 104 F 5 C to 40 C Storage Temperature 4 F to 140 F 20 C to 60 C Operating Humidity Max 80 up to 87 F 31 C decreasing linearly to 50 at 104 F 40 C Sto...

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