Greenlee DM-50 User manual

999 3790.5 © 2004 Greenlee Textron IM 1465 REV 1 1/ 04
DM-50 • DM-55
Digital
Multimeters
Multimetros
Digitales
Multimetres
Numeriques
INSTRUCTION MANUAL
MANUAL DE INSTRUCCIONES
MANUEL D’INSTRUCTIONS
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 estas herramientas o darles 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-50 and DM-55 Digital Multimeters are hand-held
testing devices with the following measurement capabilities: AC and DC
voltage, DC current, and resistance. The units also check diodes.
The DM-50 also tests 1.5 V and 9 V batteries. The DM-55 also measures
temperature (K-type thermocouples) and verifies continuity. In addition,
the units feature a 3-1/2–digit LCD, manual range selection, overload
protection, and permanently connected leads and probes which can be
stored on the protective boot.
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
This instruction manual is intended to familiarize all personnel with the
safe operation and maintenance procedures for Greenlee DM-50 and
DM-55 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 shall not be liable for damages resulting from
misapplication or misuse of its products.

DM-50 • DM-55
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.

4
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.
Important Safety Information
Electric shock hazard:
Contact with live circuits could result in
severe injury or death.
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.
• Inspect the test leads 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.

DM-50 • DM-55
5
Important Safety Information
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.
• Do not operate with the case open.
• Before opening the case, remove the test leads from the circuit
and shut off the unit.
Failure to observe these warnings could result in severe injury or
death.
The fuse is an integral part of the overvoltage protection. When
fuse replacement is necessary, see 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.

6
Important Safety Information
• Unless measuring voltage or current, 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.
• 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. See Specifications.
Failure to observe these precautions may result in injury and can
damage the unit.
Do not change the measurement function or range 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-50 • DM-55
7
Identification
1. Display
2. Selector to select a
function or turn
power off
3. Thermocouple input
for K-type thermo-
couple (DM-55 only)
4. Permanently
attached test leads
and probes
Display Icons
5. HV 200.0 V or 300 V AC
or DC range selected
(DM-50 only)
6. – Polarity
7. Low battery
Symbols on the Unit
Warning—Read the instruction manual
Battery
Double insulation
3
4
2
1
5
6
7

8
Electric shock hazard:
Contact with live circuits could result in
severe injury or death.
Operation
1. Set the selector according to the Settings Table.
Start with the highest measurement setting.
2. See Typical Measurements for illustrations of typical uses.
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. See the address shown under Warranty.
4. Take the reading from the circuit or component to be tested. If the
resolution is not satisfactory, remove the leads from the circuit and
change to the next lower range.

DM-50 • DM-55
9
Operation (cont’d)
Settings Table
* Connect the unit in series with the test object and then
switch the test object on.
** Tone sounds if the measured resistance is less than
approximately 30 Ω.
*** The DM-55 has a built in sensor that measures ambient
temperature and operates in the range of 32 °F to 104 °F.
An external K-type thermocouple can be plugged into the
thermocouple input. See the Accuracy section for ranges
and accuracies.
To measure this set the selector
characteristic … to this symbol …
DC Voltage V
AC Voltage V
DC Current* mA
(DM-50)
DC Current* A
(DM-55)
Resistance Ω
Continuity**
(DM-55)
Diode
Battery BATT TEST
(DM-50)
Temperature*** TEMP
(DM-55)

10
Typical Measurements
Current Measurement
Voltage
Measurement

DM-50 • DM-55
11
Typical Measurements
Continuity
Check
Resistance
Measurement

12
Typical Measurements
Temperature Measurement
Diode
Measurement
Reverse Bias
Forward Bias
Red
Probe

DM-50 • DM-55
13
Accuracy
See the Specifications section for operating conditions.
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 80% relative
humidity.
AC Voltage (450 kΩimpedance)
DC Voltage (1 MΩimpedance)
Model Range Accuracy Overload Protection
DM-50 200.0 V ±(1.5% + 0.4 V) 300 VDC/300 V RMS
DM-55 300 V ±(2.0% + 4 V) AC
Model Range Accuracy Overload Protection
2.000 V ±(1.2% + 0.002 V)
DM-50 20.00 V ±(1.2% + 0.02 V)
200.0 V ±(1.2% + 0.2 V)
300 V ±(1.5% + 2 V) 300 VDC/300 V RMS
200.0 mV ±(1.2% + 0.2 mV) AC
2000 mV ±(1.2% + 2 mV)
DM-55 20.00 V ±(1.2% + 0.02 V)
200.0 V ±(1.2% + 0.2 V)
300 V ±(1.9% + 2 V)

14
Accuracy (cont’d)
DC Current
Resistance
Model Range Accuracy Overload Protection
2.000 kΩ±(1.5% + 0.005 kΩ)
DM-50 20.00 kΩ±(1.5% + 0.05 kΩ)
200.0 kΩ±(1.5% + 0.5 kΩ)
2.000 MΩ±(2.0% + 0.004 MΩ)
200.0 Ω±(1.5% + 0.5 Ω) 250 V AC/DC
2000 Ω±(1.5% + 5 Ω)
DM-55 20.00 kΩ±(1.5% + 0.05 kΩ)
200.0 kΩ±(1.5% + 0.5 kΩ)
2000 kΩ±(2.0% + 4 kΩ)
Model Range Accuracy Overload Protection
DM-50 200.0 mA ±(2.5% + 0.4 mA)
200.0 µA±(2.5% + 0.4 µA) Fuse
DM-55 2000 µA±(2.5% + 4 µA) 200 mA/250 V F
20.00 mA ±(2.5% + 0.04 mA)
200.0 mA ±(2.5% + 0.4 mA)

DM-50 • DM-55
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Accuracy (cont’d)
Temperature (measures in °F)
*The accuracy information for temperature is for the meter only.
Diode Test
Test Current: Approximately 1.0 mA
Test Voltage:
DM-50: Maximum 2.8 V
DM-55: Maximum 2.3 V
Continuity Test (DM-55)
Threshold: Tone sounds if the measured resistance is less than
approximately 30 Ω.
Battery Test (DM-50)
Test Current: Approximately 14 mA for 1.5 V, 8 mA for 9 V
Accuracy: ±(5% + 0.1 V)
Model Range Accuracy*
32 °F to 104 °F not
(internal sensor) specified
DM-55 –40 °F to 752 °F±(2.5% + 9 °F)
752 °F to 1832 °F±(2.5% + 18 °F)

16
Specifications
Display: 3-1/2–digit LCD (1999 maximum count)
Overrange Indication: “1”appears on the left side of the display
Polarity Indication: “–” appears for negative values
Sampling Rate: Approximately 2.5 per second
Fuse: 200 mA/250 V F, interrupting rating 1.5 kA, 5 x 20 mm
Overvoltage Protection Category:
+ Terminal: Category II, 300 VAC and 300 VDC
Operating Conditions: 0 °C to 40 °C (32 °F to 104 °F),
0% to 80% relative humidity
Elevation: 2000 m (6500') maximum
Indoor use only
Storage Conditions: –20 °C to 55 °C (–4 °F to 131 °F),
0% to 80% relative humidity
Remove battery
Pollution Degree: 2
Battery: 9 V battery (NEDA 1604, JIS 006P or IEC 6LR61)

DM-50 • DM-55
17
Overvoltage Installation Categories
These definitions were derived from the international safety standard
for insulation coordination as it applies to measurement, control, and
laboratory equipment. These overvoltage categories are explained in
more detail by the International Electrotechnical Commission; refer to
either of their publications: IEC 1010-1 or IEC 60664.
Overvoltage Category I
Signal level. Electronic and telecommunication equipment, or parts
thereof. Some examples include transient-protected electronic circuits
inside photocopiers and modems.
Overvoltage Category II
Local level. Appliances, portable equipment, and the circuits they are
plugged into. Some examples include light fixtures, televisions and long
branch circuits.
Overvoltage Category III
Distribution level. Permanently installed machines and the circuits they
are hard-wired to. Some examples include conveyor systems and the
main circuit breaker panels of a building’s electrical system.
Overvoltage Category IV
Primary supply level. Overhead lines and other cable systems. Some
examples include cables, meters, transformers and other exterior
equipment owned by the power utility.

18
Maintenance
•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. See Specifications.
Failure to observe these precautions may result in injury and can
damage the unit.
Battery and Fuse Replacement
Before opening the case, remove the test leads from the circuit
and shut off the unit.
Failure to observe this warning could result in severe injury or
death.
1. Disconnect the unit from the circuit.
2. Turn the unit off.
3. Remove the screws from the back cover.
4. Remove cover.
5. Replace the battery (observe polarity) and/or fuse.
6. Replace the back cover and screws.
Cleaning
Periodically wipe the case with a damp cloth and mild detergent; do not
use abrasives or solvents.

DM-50 • DM-55
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Descripción
Los Multímetros digitales modelos DM-50 y DM-55 de Greenlee son
instrumentos de verificación capaces de efectuar los siguientes tipos de
mediciones: tensión alterna y continua, corriente continua, y resistencia.
Estas unidades son de bolsillo y caben perfectamente en la palma de la
mano. Estas unidades también sirven para verificar diodos.
El modelo DM-50 igualmente verifica pilas de 1,5V y 9V. Además, el modelo
DM-55 es capaz de efectuar mediciones de temperatura (con termocuplas
tipo “K”), y verificar continuidad. Asimismo, las unidades incluyen una
pantalla LCD de 3-1/2 dígitos, selección manual de escala, protección contra
sobrecargas, además de sondas y cables de prueba permanentemente
conectados que pueden almacenarse en el accesorio protector.
Acerca de la seguridad
Es fundamental observar métodos seguros al utilizar y dar mantenimiento
a las herramientas y equipo Greenlee. Este manual de instrucciones y todas
las marcas que ostenta la herramienta le ofrecen la información necesaria
para evitar riesgos y hábitos poco seguros relacionados con su uso. Siga
toda la información sobre seguridad que se proporciona.
Propósito de este manual
Este manual de instrucciones tiene como propósito familiarizar a todo el
personal con los procedimientos de operación y mantenimiento seguros
para los Multímetros digitales modelos DM-50 y DM-55 de Greenlee.
Manténgalo siempre al alcance de todo el personal. Puede obtener copias
adicionales de manera gratuita, previa solicitud.
CONSERVE ESTE MANUAL
Todas las especificaciones son nominales y pueden cambiar conforme tengan
lugar mejoras de diseño. Greenlee Textron no se hace responsable de los daños
que puedan surgir de la mala aplicación o mal uso de sus productos.

20
Importante Información sobre Seguridad
Este símbolo se utiliza para indicar un riesgo o práctica poco segura
que podría ocasionar lesiones o daños materiales. Cada uno de los
siguientes términos denota la gravedad del riesgo. El mensaje que
sigue a dichos términos le indica cómo puede evitar o prevenir ese
riesgo.
SÍMBOLO DE ALERTA
SOBRE SEGURIDAD
Peligros inmediatos que, de no evitarse, OCASIONARÁN graves
lesiones o incluso la muerte.
Peligros que, de no evitarse, PODRÍAN OCASIONAR graves lesiones
o incluso la muerte.
Peligro o prácticas peligrosas que, de no evitarse, PUEDEN
OCASIONAR lesiones o daños materiales.