Amprobe PM51A User manual

PM51A
Pocket Multimeter
Users Manual
•Mode d’emploi
•Bedienungshandbuch
•Manual d’Uso
•Manual de uso
PN 2728847
July 2006
© 2006 AmprobeTest Tools.
All rights reserved. Printed in Taiwan
English

SELECTSELECT
4
1
2
3
5
PM51A
ALCD display
BRotary switch to select functions and to turn the power on or off
CSELECT-button to select alternate functions.
DPermanently attached red test lead for positive (+) polarity and black test lead for ground
reference (-)
EHOLD button to freeze the display for later viewing.

1
PM51A Pocket Meter
Contents
Introduction......................................................................................................................2
Safety Information............................................................................................................2
Symbols Used in this Manual ........................................................................................3
Making Measurements .....................................................................................................3
Selecting Functions........................................................................................................3
V dc and V ac Functions ................................................................................................3
Resistance, Continuity, Diode, and Capacitance Functions ............................................4
Frequency Function........................................................................................................5
Additional Features ........................................................................................................5
Product Maintenance........................................................................................................5
Maintenance ..................................................................................................................5
Cleaning.........................................................................................................................5
Troubleshooting.............................................................................................................5
Battery Replacement......................................................................................................6
Limited Warranty and Limitation of Liability .....................................................................6
Repair ...............................................................................................................................7
Specifications ...................................................................................................................7

2
Introduction
The PM51A meter is a shirt-pocket size meter only 19 mm (.75 in) wide and weighing less than 85 g
(3 oz). With full functionality offering AC and DC voltage to 600 V, resistance to 40 MΩ, capacitance
to 300 µF, frequency to 1 MHz, continuity with beeper, and diode test. Fully autoranging, the PM51A
offers seven different measurement functions with 27 full ranges of measurement. The digital display
is oversized with large digits and icons in the display. In spite of its small size, the PM51A is full
safety rated to CAT III 300 V, CAT II 600 V, and is UL listed. No other meter offers this size with such
performance and high safety ratings.
Safety Information
•The PM51A Digital Multimeter is certified for cULus and EN61010-1:2001; CAT II 600 V, CAT III
300 V, class 2 and pollution deg. 2.
•This instrument is EN61010-1 certified for Installation Category II
(600 V). It may only be used to make measurements on energy limited circuits within equipment
and not directly connected to mains.
•This instrument is EN61010-1 certified for Installation Category III
(300 V). It is recommended for use with local level power distribution, appliances, portable
equipment, etc., where only smaller transient overvoltages may occur, and not for primary supply
lines, overhead lines and cable systems.
•Do not exceed the maximum overload limits per function (see specifications) nor the limits
marked on the instrument itself. Never apply more than 600 V between the test lead and earth
ground.
•Inspect the DMM, test leads and accessories before every use. Do not use any damaged part.
•Never ground yourself when taking measurements. Do not touch exposed circuit elements or test
probe tips.
•Do not operate the instrument in an explosive atmosphere.
•Exercise extreme caution when: measuring voltage >20 V // current >10 mA // AC power line with
inductive loads // AC power line during electrical storms // current, when the fuse blows in a
circuit with open circuit voltage > 600 V // servicing CRT equipment.
•Remove test leads from circuit before opening the case.

3
Symbols Used in this Manual
N Battery WRefer to the manual
TDouble insulated XDangerous Voltage
FDirect Current JEarth Ground
BAlternating Current RAudible tone
PComplies with EU directives >
Underwriter Laboratories, Inc.
Making Measurements
All measurements described in this manual use the red test lead for positive (+) polarity and the
black test lead for ground reference (-) unless otherwise specified.
Power On and Off
Turn the rotary switch to turn the power ON or OFF.
Selecting Functions
Select measurement as shown in the diagram on the back of the meter.

4
V dc and V ac Functions
Rotate the rotary selector to the Vposition. V dc is the default function. The dc annunciator F
appears on the display. Press the SELECT button momentarily to select V ac. The ac annunciator B
appears on the display.
Resistance, Continuity, Diode, and Capacitance Functions
•Turn the rotary switch to the Ω/R/G/position. Resistance is the default function.
1. Turn off power to the circuit being measured. Never measure resistance across a voltage source
or on a powered circuit.
2. Discharge any capacitors that may influence the reading.
3. Connect the test probes across the resistance.
4. Read the display. If OL appears on the highest range, the resistance is too large to be measured
or the circuit is an open circuit.
•A continuous beep tone indicates a complete circuit.
1. Turn off power to the circuit being measured.
2. Discharge any capacitors that may influence the reading.
3. Connect the test probes across the resistance or two measurement nodes.
4. Listen for the tone that indicates continuity (< 120 Ω).
•Press the SELECT button momentarily AGAIN to select Diode test function. The annunciator G
appears on the display. The reading shows the approximate voltage drop across the test leads.
Normal forward voltage drop (forward biased) for a good silicon diode is between 0.400 V to
0.900 V. A reading higher than that indicates a leaky diode (defective). A zero reading indicates a
shorted diode (defective). OL indicates an open diode (defective). Reverse the test leads
connections (reverse biased) across the diode. The digital display shows OL if the diode is good.
Any other readings indicate the diode is defective.
•Press the SELECT button momentarily AGAIN to select the Capacitance function.
1. Turn off power to the circuit being measured.
2. Discharge the capacitor using a 100 kW resistor.
3. Free at least one end of the capacitor from the circuit.
4. Connect the test probes across the capacitor.
5. Read the display.

5
Frequency Function
Turn the rotary switch to the Hz position to select the frequency function.
This function is set only at the highest input sensitivity mainly for measuring small electronic signals
below 20 V ac rms.
1. Connect the test probes to the signal source.
2. Read the display.
Additional Features
HOLD and 30 ms MAX HOLD Modes
HOLD mode freezes the display for later viewing. Press the HOLD button momentarily to activate or
to exit the Hold feature.
MAX mode captures voltage signals that have durations as short as 30 ms (milliseconds) within a
single range, and has automatic up range capability. This feature is available in V dc and V ac
functions. Press the HOLD button for 1 second or more to activate or exit MAX mode.
XWWARNING
Hazardous voltages present at test leads may not be displayed when in HOLD
mode.
Auto-ranging
If the function selected has more than one range, the meter will auto-range to the best range and
resolution.
Product Maintenance
Maintenance
Do not attempt to repair this meter. It contains no user serviceable parts. Repair or servicing should
only be performed by qualified personnel.
Cleaning
Periodically wipe the case with a damp cloth and mild detergent; do not use abrasives or solvents. If
the meter is not to be used for periods of longer than 60 days, remove the battery and store it
separately
Troubleshooting
If the instrument fails to operate, check battery, leads, and replace as necessary. Double check
operating procedure as described earlier in this manual. Refer to the LIMITED WARRANTY section
for obtaining warranty or repairing service.

6
Battery Replacement
If the meter starts up with persistent resetting display or with low battery icon Nturns on, replace
the battery. The meter uses one 3 V coin battery, IEC-CR2032.
To replace the battery
1. Turn off the meter and disconnect the test leads from live circuits.
2. Loosen the screw on the case bottom.
3. Lift the end of the case bottom nearest the input test leads until it unsnaps from the case top.
Replace the battery cover and tighten the screw. Recycle the battery using approved methods.
4. Replace the battery. Observe battery polarities with positive (+) faces up (towards the case
bottom). Replace the case bottom, and ensure that the snap on the case top (near the LCD side)
is engaged.
5. Replace and tighten the screw.
XWWARNING
To avoid electrical shock, disconnect test leads from live circuits before opening
the case. Do not operate with open case.
Limited Warranty and Limitation of Liability
Your Amprobeproduct will be free from defects in material and workmanship for 1 year from the
date of purchase. This warranty does not cover fuses, disposable batteries or damage from accident,
neglect, misuse, alteration, contamination, or abnormal conditions of operation or handling.
Resellers are not authorized to extend any other warranty on Amprobe’s behalf. To obtain service
during the warranty period, return the product with proof of purchase to an authorized Amprobe
Test Tools Service Center or to a Amprobedealer or distributor. See Repair Section for details.
THIS WARRANTY IS YOUR ONLY REMEDY. ALL OTHER WARRANTIES - WHETHER EXPRESS,
IMPLIED OR STAUTORY - INCLUDING IMPLIED WARRANTIES OF FITNESS FOR A PARTICULAR
PURPOSE OR MERCHANTABILITY, ARE HEREBY DISCLAIMED. MANUFACTURER SHALL NOT BE
LIABLE FOR ANY SPECIAL, INDIRECT, INCIDENTAL OR CONSEQUENTIAL DAMAGES OR LOSSES,
ARISING FROM ANY CAUSE OR THEORY. Since some states or countries do not allow the exclusion
or limitation of an implied warranty or of incidental or consequential damages, this limitation of
liability may not apply to you.

7
Repair
All test tools returned for warranty or non-warranty repair or for calibration should be accompanied
by the following: your name, company’s name, address, telephone number, and proof of purchase.
Additionally, please include a brief description of the problem or the service requested and include
the test leads with the meter. Non-warranty repair or replacement charges should be remitted in the
form of a check, a money order, credit card with expiration date, or a purchase order made payable
to AmprobeTest Tools.
In-Warranty Repairs and Replacement – All Countries
Please read the warranty statement and check your battery before requesting repair. During the
warranty period any defective test tool can be returned to your AmprobeTest Tools distributor for
an exchange for the same or like product. Please check the “Where to Buy” section on
www.amprobe.com for a list of distributors near you. Additionally, in the United States and Canada
In-Warranty repair and replacement units can also be sent to a AmprobeTest Tools Service Center
(see below for address).
Non-Warranty Repairs and Replacement – US and Canada
Non-warranty repairs in the United States and Canada should be sent to a AmprobeTest Tools
Service Center. Call AmprobeTest Tools or inquire at your point of purchase for current repair and
replacement rates.
InUSA InCanada
AmprobeTest Tools AmprobeTest Tools
Everett, WA 98203 Mississauga, ON L4Z 1X9
Tel: [phone] Tel: [phone]
Fax: [phone] Fax: [phone]
Non-Warranty Repairs and Replacement – Europe
European non-warranty units can be replaced by your AmprobeTest Tools distributor for a nominal
charge. Please check the “Where to Buy” section on www.amprobe.com for a list of distributors near
you.
European Correspondence Address*
AmprobeTest Tools Europe
P.O. Box 1186
5602 BD Eindhoven
The Netherlands
*(Correspondence only – no repair or replacement available from this address. European customers
please contact your distributor).
Specifications
General Specifications

8
Display and Update Rate: 3-3/4 digits 4000 counts; Updates 3 per second
nominal
Operating Temperature: 0 °C - 40 °C
Relative Humidity: Maximum 80% R.H. up to 31 °C, decreasing linearly to
50% R.H. at 40 °C
Altitude: Operating below 2000 m
Storage Temperature: -20 °C ~ 60 °C, < 80% R.H. (with battery removed)
Temperature Coefficient: Nominal 0.15 x (specified accuracy)/ °C @
(0°C ~ 18 °C or 28 °C ~ 40 °C), or otherwise specified
Sensing: Average sensing
Overload Protection: 600 V dc and V ac rms
Low Battery: Below approx. 2.4 V
Power Supply: 3 V standard button battery x 1
(IEC-CR2032; ANSI-NEDA-5004LC)
Power Consumption (typical): 2 mA
APO Consumption (typical): 2.2 µA
APO Timing: Idle for 30 minutes
Dimension / Weight
L 113 mm x W 53 mm x H 10.2 mm / Approx. 78 gm