Greenlee DM-300 User manual

DM-300 • DM-310
DM-330 • DM-350
Digital
Multimeters
Multímetros
digitales
Multimètres
numériques
INSTRUCTION MANUAL
MANUAL DE INSTRUCCIONES
MANUEL D’INSTRUCTIONS
999 6757.0 REV 1 © 2004 Greenlee Textron Inc. 12/04
Read and understand all of the instructions and
safety information in this manual before
operating or servicing this tool.
Lea y entienda todas las instrucciones y la
información sobre seguridad que aparecen en
este manual, antes de manejar esta herramienta
o darle mantenimiento.
Lire attentivement et bien comprendre toutes les
instructions et les informations sur la sécurité de
ce manuel avant d‘utiliser ou de procéder à
l‘entretien de cet outil.

2
Description
The Greenlee DM-300, DM-310, DM-330, and DM-350 Digital Multimeters
are hand-held testing devices with the following measurement
capabilities: AC and DC voltage, frequency, and resistance. They also
check diodes and verify continuity. These meters have non-contact and
single-probe voltage detection capability.
The DM-310, DM-330, and DM-350 multimeters have the following
additional measurement capabilities: AC and DC current, and capacitance.
They warn the user with a beep and error message on the LCD if the test
lead is plugged into the A input terminal while the selector switch is not in
the A position.
The DM-350 multimeter has additional low-current ranges for AC and DC
current measurement as well as a backlit display.
Safety
Safety is essential in the use and maintenance of Greenlee tools and
equipment. This instruction manual and any markings on the tool provide
information for avoiding hazards and unsafe practices related to the use of
this tool. Observe all of the safety information provided.
Purpose of This Manual
This instruction manual is intended to familiarize all personnel with the
safe operation and maintenance procedures for the Greenlee DM-300,
DM-310, DM-330, and DM-350 Digital Multimeters.
Keep this manual available to all personnel.
Replacement manuals are available upon request at no charge.
KEEP THIS MANUAL
All specifications are nominal and may change as design improvements occur. Greenlee
Textron Inc. shall not be liable for damages resulting from misapplication or misuse of
its products.
® Registered: The color green for electrical test instruments is a registered trademark
of Greenlee Textron Inc.

DM-300 • DM-310 • DM-330 • DM-350
3
Important Safety Information
This symbol is used to call your attention to hazards or unsafe
practices which could result in an injury or property damage. The
signal word, defined below, indicates the severity of the hazard. The
message after the signal word provides information for preventing or
avoiding the hazard.
SAFETY ALERT SYMBOL
Immediate hazards which, if not avoided, WILL result in severe injury
or death.
Hazards which, if not avoided, COULD result in severe injury or death.
Hazards or unsafe practices which, if not avoided, MAY result in injury
or property damage.
Read and understand this material before
operating or servicing this equipment. Failure to
understand how to safely operate this tool could
result in an accident causing serious injury or
death.

4
Important Safety Information
Electric shock and fire hazard:
•Do not expose this unit to rain or moisture.
•Do not use the unit if it is wet or damaged.
•Use test leads or accessories that are appropriate for the application.
See the category and voltage rating of the test lead or accessory.
•Inspect the test leads or accessory before use. They must be clean
and dry, and the insulation must be in good condition.
•Use this unit for the manufacturer’s intended purpose only, as
described in this manual. Any other use can impair the protection
provided by the unit.
Failure to observe these warnings could result in severe injury or death.
Electric shock hazard:
Contact with live circuits could result in severe
injury or death.
Electric shock hazard:
•Do not apply more than the rated voltage between any two input
terminals, or between any input terminal and earth ground.
•Do not contact the test lead tips or any uninsulated portion of the
accessory.
Failure to observe these warnings could result in severe injury or death.

DM-300 • DM-310 • DM-330 • DM-350
5
Important Safety Information
Electric shock hazard:
•Unless measuring voltage, current, or frequency, shut off and lock
out power. Make sure that all capacitors are discharged. Voltage
must not be present.
•Set the selector and connect the test leads so that they correspond
to the intended measurement. Incorrect settings or connections can
result in a blown fuse.
•Using this unit near equipment that generates electromagnetic
interference can result in unstable or inaccurate readings.
Failure to observe these warnings could result in severe injury or death.
Electric shock hazard:
The fuse is an integral part of the overvoltage protection. When fuse
replacement is necessary, refer to “Specifications” for the correct type,
size and capacity. Using any other type of fuse will void the overvoltage
protection rating of the unit.
Failure to observe this warning could result in severe injury or death.
Electric shock hazard:
•Do not operate with the case or battery compartment open.
•Before opening the case or battery compartment, remove the test
leads from the circuit and shut off the unit.
Failure to observe these warnings could result in severe injury or death.

6
Important Safety Information
Electric shock hazard:
•Do not attempt to repair this unit. It contains no user-serviceable
parts.
•Do not expose the unit to extremes in temperature or high humidity.
Refer to “Specifications.”
Failure to observe these precautions may result in injury and can
damage the unit.
Electric shock hazard:
Do not change the measurement function while the test leads are
connected to a component or circuit.
Failure to observe this precaution may result in injury and can damage
the unit.

DM-300 • DM-310 • DM-330 • DM-350
7
Identification
1. LCD display
2. Feature buttons
3. Selector
4. Positive input terminal for high current measurements
5. Negative, common (COM), or ground input terminal for all
measurements
6. Positive input terminal for all measurements except high current
(6.000 A and 10.00 A ranges)
DM-310 • DM-330 • DM-350DM-300
1
2
3
5 6 4 5
6

8
Identification (cont’d)
Display Icons
7. Automatic ranging is enabled.
8. Hold function is enabled.
9. DC measurement is selected.
10. AC measurement is selected.
11. –Polarity indicator
12. MAX MAX MIN mode is selected.
MIN
13. O.L Overload indicator
14. µMicro (10-6)
15. F Farads
16. nNano (10-9)
17. Low battery indicator
18. Diode
19. Continuity
20. MMega (106)
21. kKilo (103)
22. ΩOhms
23. mMilli (10-3)
23. VVolts
24. Hz Hertz (frequency in cycles per second)
7
8
9–10
11
12
17–19
20–22
23–25
14–16
13
Note: Unidentified
icons are not used on
these models.
Symbols on the Unit
Warning—Read the instruction manual
Double insulation

DM-300 • DM-310 • DM-330 • DM-350
9
Using the Features
•Automatic Power Off To extend battery life, the meter will shut itself off
after approximately 30 minutes of inactivity. To restore power, press any
button. To disable this feature, press SELECT while turning the meter
on.
•MAX MIN Press and hold to begin recording the input. “MAX MIN” will
appear on the display. The meter will beep whenever the minimum or
maximum is updated. When using the MAX MIN function, press
momentarily to cycle through the maximum, minimum, difference
(MAX – MIN). Press and hold to exit this mode.
The Automatic Power Off feature should be disabled for extended use of
MAX MIN recording.
•EFPress momentarily to detect the electric field that surrounds current-
carrying conductors. Signal strength is displayed as a series of dashes
on the display.
–Use the tester’s built-in antenna (located along the top, near the
LCD) for tracing live circuits or locating a break in a wire.
–For more precision, such as distinguishing between current-
carrying and ground wires, connect a test lead to the + input
terminal and use it as a probe.
•(DM-350 only) Press and hold until LCD illuminates. The lamp
turns off after 90 seconds to extend battery life.
•SELECT Press momentarily to toggle between functions, or to toggle
between AC and DC when measuring current.
•RANGE Press once to enter the manual ranging mode. The icon
will disappear from the display. Press repeatedly to step through the
ranges. Press and hold to return to the automatic ranging mode.
When using MAX MIN or HOLD, pressing RANGE will cause the meter to
exit that mode.
•HOLD Press momentarily to hold the present value on the display.
Press again to exit this mode.

10
*The crest factor is the ratio of the peak value to the RMS value; it is
represented by the Greek letter ξ.
AC Measurement
AC measurements are usually displayed as RMS (root mean squared)
values. Two methods of AC measurement are average-responding RMS
calibrated and true RMS-reading.
The average-responding RMS calibrated method takes the average value of
the input signal, multiplies it by 1.11, and displays the result. This method
is accurate if the input signal is a pure sine wave. The Greenlee DM-310 is
an average-responding meter.
The true RMS-reading method uses internal circuitry to read the true RMS
value. This method is accurate, within the specified crest factor limitations,
whether the input signal is a pure sine wave, a square wave, sawtooth
wave, half wave or signal with harmonics. The ability to read true RMS
provides much more measurement versatility. The Greenlee DM-300,
DM-330, and DM-350 are true RMS meters.
The Waveforms and Crest Factors table shows some typical AC signals and
their RMS values.
Waveforms and Crest Factors
Waveform
RMS Value 100 100 100 100
Rectified Value 90 100 87 64
Crest Factor* 1.414 1 1.73 2
(ξ)

DM-300 • DM-310 • DM-330 • DM-350
11
Operation
1. Refer to the Settings Table. Set the selector to the proper setting,
press SELECT (when instructed to do so), and connect the test leads
to the meter.
2. Refer to “Typical Measurements” for specific measurement
instructions.
3. Test the unit on a known functioning circuit or component.
•If the unit does not function as expected on a known functioning
circuit, replace the battery and/or fuse.
•If the unit still does not function as expected, send the unit to
Greenlee for repair. Refer to the instructions under the Warranty.
4. Take the reading from the circuit or component to be tested.
Electric shock hazard:
Contact with live circuits could result in severe
injury or death.

12
Settings Table
*Tone indicates continuity. The threshold is between 10 Ωand 150 Ω.
**Discharge capacitor before measurement. Discharge a large capacitor
through an appropriate resistive load.
†Default measurement is AC. Press SELECT to measure DC current.
Operation (cont’d)
Connect
the black
lead to:
Set the
selector
to this symbol:
Connect
the red
lead to:
This icon
will appear
on the display:
To measure
this value:
All Models
DM-310, DM-330, and DM-350 Only
COM
and press
SELECT
or
Hz
Frequency
of a voltage
signal
COMResistance
COM
and press
SELECT
Continuity*
COM
and press
SELECT
2 times
andDiode
COM
and press
SELECT
2 times
Hz
Frequency
of a current
(10 A max)
COM
and A
(µAon DM-350)
Current
(10 A max)†
COM
and press
SELECT
3 times
F
Capacitance**
and
and COM
Voltage
(1000 V max)
DM-350 Only
COM
and µA
Current
(2000 µA max)†
COM
Hz
Frequency
of a current
(2000 µA max)
and press
SELECT
2 times

DM-300 • DM-310 • DM-330 • DM-350
13
Typical Measurements
Voltage Measurement
DM-310
DM-330
DM-350
DM-300

14
Typical Measurements
Electric Field Detection
DM-310
DM-330
DM-350
DM-300
A
B
A–Non-contact
OR
B–Contact

DM-300 • DM-310 • DM-330 • DM-350
15
Resistance Measurement
Typical Measurements
DM-310
DM-330
DM-350
DM-300

16
Continuity Check
Typical Measurements
DM-310
DM-330
DM-350
DM-300

DM-300 • DM-310 • DM-330 • DM-350
17
Typical Measurements
Diode Measurement
DM-310
DM-330
DM-350
DM-300
Forward Bias
Reverse Bias
Forward Bias
Reverse Bias

18
Typical Measurements
Current Measurement—
DM-310, DM-330, and DM-350 Only
Capacitance Measurement—
DM-310, DM-330, and DM-350 Only

DM-300 • DM-310 • DM-330 • DM-350
19
Accuracy
Refer to “Specifications” for operating conditions and temperature
coefficient.
Accuracy is specified as follows: ±(a percentage of the reading + a fixed
amount) at 23 °C ±5 °C (73.4 °F ±9 °F), 0% to 75% relative humidity.
True RMS readings: DM-300, DM-330, and DM-350 AC accuracies are
specified from 5% (10% for 600.0 mV range) to 100% of the range unless
otherwise specified. Frequency must be within the specified bandwidth for
non-sinusoidal waveforms. Crest factors are as follows:
•Crest factor < 2:1 at full scale
•Crest factor < 4:1 at half scale
DC Voltage
Range Accuracy
600.0 mV 0.7% + 0.2 mV
6.000 V 0.5% + 0.003 V
60.00 V 0.5% + 0.03 V
600.0 V 0.7% + 0.2 V
1000 V 1.2% + 6 V
Input Impedance: 1000 MΩ
nominal for 600.0 mV range;
10 MΩnominal for all other
ranges
AC Voltage
Accuracy at
Range 50 Hz to 500 Hz
600.0 mV 1.2% + 0.3 mV
6.000 V 1.0% + 0.003 V
60.00 V 1.0% + 0.03 V
600.0 V 1.0% + 0.3 V
1000 V 2.5% + 6 V
Input Impedance: 10 MΩ|| 90 pF
nominal
Ohms
Range Accuracy
600.0 Ω0.8% + 0.4 Ω
6.000 kΩ0.7% + 0.002 kΩ
60.00 kΩ0.7% + 0.02 kΩ
600.0 kΩ0.7% + 0.2 kΩ
6.000 MΩ0.9% + 0.004 MΩ
60.00 MΩ2.0% + 0.04 MΩ
600 Ωwith Continuity Beeper
Range Accuracy
600.0 Ω0.8% + 0.4 Ω
Continuity Beeper Response:
< 100 µs
Open Circuit Voltage:
0.4 VDC typical
Audible Threshold:
Between 10 Ωand 150 Ω
Diode Tester
Open Circuit
Test Current Voltage Accuracy
0.4 mA typical < 1.6 VDC typical 1.9% + 0.003 V

20
Accuracy (cont’d)
Non-contact EF Detection
Typical Voltage Bar Graph Indication
20 V to 60 V –
40 V to 80 V – –
60 V to 110 V – – –
80 V to 150 V – – – –
above 120 V – – – – –
Indication: Bar graph segments and audible beep tones proportional to the
field strength
Detection Frequency: 50/60 Hz
Detection Antenna: Top end of the meter
Frequency
Sensitivity Range— Range—
Function (Sine RMS) AC Functions DC Functions
All Models
600.0 mV 400 mV 40 Hz to 500 Hz 40 Hz to 500 Hz
6.000 V 4 V 40 Hz to 60 kHz 40 Hz to 30 kHz
60.00 V 6.0 V 40 Hz to 60 kHz 40 Hz to 30 kHz
600.0 V 60 V 40 Hz to 60 kHz 40 Hz to 30 kHz
1000 V 600 V 40 Hz to 100 Hz 40 Hz to 100 Hz
DM-310, DM-330, and DM-350 Only
6.000 A 5 A 40 Hz to 6 kHz 40 Hz to 6 kHz
10.00 A 5 A 40 Hz to 6 kHz 40 Hz to 6 kHz
DM-350 Only
600.0 µA300 µA40 Hz to 10 kHz 40 Hz to 10 kHz
2000 µA300 µA40 Hz to 10 kHz 40 Hz to 10 kHz
Accuracy of Frequency Ranges
Display Range Accuracy
9.999 Hz Not specified
99.99 Hz ±(0.05% + 0.01 Hz)
999.9 Hz ±(0.05% + 0.1 Hz)
9.999 kHz ±(0.05% + 0.001 kHz)
99.99 kHz ±(0.05% + 0.01 kHz)