Amprobe PM55A User manual

PM55A
Automatic Precision Pocket Meter
Users Manual
•Mode d’emploi
•Bedienungshandbuch
•Manuale d’Uso
•Manual de uso
PN 2728864
July 2006
© 2006 AmprobeTest Tools.
All rights reserved. Printed in Taiwan
English

SELECT
4
1
2
3
Press for 2 seconds
to turn meter on.
PM55A
ALCD display
BRotary switch to select functions
CSELECT-button to select alternate functions and turn the power off and on.
DPermanently attached red test lead for positive (+) polarity and black test lead for ground
reference (-)

1
PM55A Pocket Meter
Contents
Introduction........................................................................................................2
Safety Information..............................................................................................2
Symbols Used in this Manual ..........................................................................3
Turning the Meter On and Off .............................................................................3
Making Measurements .......................................................................................4
AutoTectMode ..............................................................................................4
Continuity, Audible With Symbolic Display......................................................5
Electric Field EF-Detection, VolTect..............................................................5
Voltage.............................................................................................................7
Resistance .......................................................................................................7
Frequency ........................................................................................................7
Capacitance .....................................................................................................7
V dc, V ac, and Line-Level Hz...........................................................................7
Diode ...............................................................................................................7
600 Ω..............................................................................................................8
µA dc and µA ac ..............................................................................................8
Product Maintenance..........................................................................................8
Maintenance ....................................................................................................8
Cleaning...........................................................................................................8
Troubleshooting...............................................................................................8
Battery Replacement........................................................................................8
Repair .................................................................................................................9
Specifications ...................................................................................................11

2
Introduction
This unique meter has a full complement of features in a package only 3/8 inch thick, weighing less
than 3 oz. for the utmost in shirt-pocket portability. The PM55A is fully autoranging and has an
oversized, easy-to-read digital display. With an AutoTect™ feature that enables the meter to detect
and display measurements of AC Volts, DC Volts and Resistance. The PM55A offers VolTect™, a
built-in non-contact voltage detection of AC voltage. Although very small, this meter is fully UL safety
rated to CAT III levels and is UL listed. The AmprobePM55A precision meter includes
measurement extras such as capacitance, frequency, DC microamps and safety extras such as
transient protection to 4 kV and overload protection to 600 V.
Safety Information
•The PM55A 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.

3
•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.
•Always measure current in series with the load – NEVER ACROSS a voltage source.
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.
Turning the Meter On and Off
•Press the SELECT button for approximately 2 seconds to turn the meter on.
•To turn the meter off, press the SELECT button until the display goes blank.

4
Making Measurements
All measurements described in this manual use the Red test lead for positive (+) polarity and Black
test lead for Ground reference (-) unless otherwise specified
AutoTectmode is the default function in Auto V-Ωposition. Press the SELECT button momentarily
to select and step through the functions:
•AutoTect
•Continuity
•EF
•ACV
•DCV
•Ω
•Hz
•Cx
•AutoTect

5
AutoTectMode
This AutoTectfeature automatically selects measurement function of
V dc, V ac, or resistance based on the input via the test leads.
●With no input, the meter displays Auto when it is ready.
●With no voltage signal but a resistance below 6 MΩis present, the meter displays the resistance
value.
●When a signal above the threshold of 1.2 V dc or 1.5 V ac up to the rated 600 V is present, the
meter displays the appropriate voltage value in dc or ac, whichever larger in peak magnitude. The
Happears indicating ac V. The default of no icon is dc V.
●The AutoTecttest mode input impedance is lower than most digital multimeters and LoZ is
displayed on the LCD. Switch to the manually selected V dc or V ac, if the circuit being tested is
sensitive to the meter input impedance. Input impedance is approximately 900 Ω, helping
determine if voltage is from leakage (so-called “ghost” voltages) or a hard connection. “Ghost”
voltages will be zeroed out by the low input impedance.
●Overload-Alert Feature
When more than 600 V is present, the meter displays OL with a warning beep tone. Disconnect
the test leads from the signal immediately to avoid hazards.
•Range-Lock Feature
When a measurement reading is displayed in the AutoTectmode, press the SELECT button
momentarily to lock the function-range. The LCD annunciator Auto turns off. Range-lock can
speed up repetitive measurements. Press the SELECT button momentarily again to return to
AutoTectmode.
•When making resistance measurements in AutoTectmode, an unexpected display of voltage
readings alerts you that the circuit under test is still energized.
Continuity, Audible With Symbolic Display
With Auto on the LCD, press the SELECT button once to select Continuity function. The meter will
show a symbolic open-switch display when it is ready. A continuous beep tone and a symbolic
closed-switch indicates a closed circuit. Continuity is used for checking wiring connections and
operation of switches.
Electric Field EF-Detection, VolTect
With Auto displayed on the LCD, press the SELECT button momentarily 2 times to select the EF-
Detection feature. The meter displays EF when it is ready. Signal strength is indicated as a series of
bargraph segments on the display and variable beep tones. See the VolTectspecifications later in
this manual for a complete description of the bar graph indicators.
•An antenna is located at the top left corner of the meter, which detects electric field surrounding
current-carrying conductors. It is ideal for tracing live wiring connections, locating wiring
breakage and to distinguish between live or earth connections.

6
•For more precise indication of live wires, such as distinguishing between live and ground
sockets, use or V ac manual function selection for direct contact voltage measurements.
Note
For Maximum sensitivity, hold the meter away from the VolTect  corner.
SELECT SELECT
PM55A

7
Voltage
With Auto on the LCD, press the SELECT button 3 times to select V ac function. The meter displays
LoZBVwhen it is ready.This function is auto-ranging.
With Auto on the LCD, press the SELECT button 4 times to select V dc. The meter displays LoZ V
when it is ready. This function is auto-ranging.
Resistance
With Auto on the LCD, press the SELECT button 5 times to select resistance function, The meter
displays MΩwhen it is ready. This function is auto-ranging.
Frequency
With Auto on the LCD, press the SELECT button 6 times to select frequency function, The meter
displays Hz when it is ready. This function is auto-ranging.
Capacitance
With Auto on the LCD, press the SELECT button 7 times to select capacitance function, The meter
displays nF when it is ready. This function is auto-ranging.
Return to Auto
Press the SELECT button 8 times to return to AutoTecttest mode.
V dc, V ac, and Line-Level Hz
Turn the rotary switch to the V position to select common impedance
Hi-Z voltage measurements. V dc is the default function. Press SELECT button momentarily to select
V ac. The AC annunciator Bappears. Press momentarily again to select the Line-Level Hz function.
Line-Level Hz input sensitivity varies automatically with V ac range selected when Line-Level Hz is
selected. Measuring the signal in V ac function WHILE selecting Line-Level Hz function in that V ac
range automatically sets the most appropriate sensitivity for higher voltage applications. This can
avoid electrical noises as in 110/220 V line voltage applications. For example, If the reading shows
zero due to insufficient signal levels, select Line-Level Hz function BEFORE making measurements (at
6 V ac range) will set the highest sensitivity.
Diode
Turn the rotary selector to the GR /600 Ωposition. Diode test is the default function. 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), and the meter will give a
long beep as continuity warning. 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 resistive or shorted (defective).

8
600 Ω
Press the SELECT button to select the lowest 600 Ωrange for lower resistance measurements. It is
an extended range to complement the AutoTectresistance function.
µA dc and µA ac
Turn the rotary switch to the µAposition, µA dc is the default function. There is no annunciator for
dc. Press the SELECT button momentarily to select µA ac. The ac annunciator Bappears.
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 battery as necessary. Double-
check operating procedure as described earlier in this manual.
If the display locks up, press the SELECT button for approximately 6 seconds to reset the
microprocessor.
If the instrument voltage-resistance input is subjected to high voltage transient (mostly caused by
lightning or switching surge to your system) by accident or abnormal conditions of operation, the
series fusible resistors will react (become high impedance) like fuses to protect the user and the
instrument. Most measuring functions through this input will then be open circuit. The series fusible
resistors and the spark gaps should then be replaced by qualified technician. Refer to the LIMITED
WARRANTY section for obtaining warranty or repairing service.
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.

9
To replace the battery
XWWARNING
To avoid electrical shock, disconnect test leads from live circuits before opening
the case. Do not operate with open case.
1. Turn off the meter.
2. Disconnect the test leads from live circuits.
3. Loosen the screwon the case bottom.
4. 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.
5. 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.
6. Replace and tighten the screw.
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.
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.

10
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).

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Specifications
General Specifications
Display and Update Rate: 3-5/6 digits 6000 counts; Updates 5 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): 6 mA for Voltage functions on Auto - V Ωposition and 2 mA for other
functions
APO Consumption (typical): 2.2 µA
APO Timing: Idle for 3 minutes
Dimension / Weight
L 113 mm x W 53 mm x H 10.2 mm / Approx. 78 gm
Special Features
AutoTect(Automatic V and Ωselection) and VolTectElectric Field Detection
Agency Approvals
P >
Safety: Meets IEC61010-1, UL61010B-1, CAN/CSA-C22.2 No. 1010.1-92,
CAT II 600 V and CAT III 300V, Pollution Degree 2, Class 2
E.M.C. Meets EN61326 (1997, 1998/A1), EN61000- 4-2 (1995), and EN61000-4-3 (1996). This
product complies with requirements of the following European Community Directives: 89/ 336/ EEC
(Electromagnetic Compatibility) and 73/ 23/ EEC (Low Voltage) as amended by 93/ 68/ EEC (CE
Marking). However, electrical noise or intense electromagnetic fields in the vicinity of the equipment
may disturb the measurement circuit. Measuring instruments will also respond to unwanted signals
that may be present within the measurement circuit. Users should exercise care and take appropriate

12
precautions to avoid misleading results when making measurements in the presence of electronic
interference.
Accessories
H-PM protective holster, VC3 soft carrying pouch, battery installed, and User’s manual
Electrical Specifications
(Accuracy @ 23 °C ±5 °C and < 75% R.H.)
RF Field @ 3 V/m: Specified accuracy + 45 d (Capacitance not specified)
DC Voltage
Range Accuracy
6.000 V ±(0.5%+3 dgt)
60.00 V ±(1.0%+5 dgt)
450.0 V ±(1.2%+5 dgt)
Input Impedance:
AutoTectLo-Z V dc: 833 kΩ(4.2 kΩwhen displaying AUTO),
90 pF nominal
MRR: > 30dB @ 50 Hz/60 Hz
CMRR: > 100dB @ DC, 50 Hz/60 Hz; Rs=1 kΩ
V dc AutoTectThreshold:
> +1.2 V dc or < -0.6 V dc nominal
Hi-Z V dc only
AC Voltage
Range Accuracy
50 Hz – 60 Hz
6.000 V, 60.00 V, 450.0 V, 600 V ±(1.5%+5 dgt)
CMRR: > 60 dB @ dc to 60 Hz, Rs=1 kΩ
Input Impedance: AutoTectLo-Z V ac: 160 kΩ, 160 pF nominal
Hi-Z ACV: 5 MΩ, 90pF nominal
ACV AutoTectThreshold: > 1.5 V ac (50 Hz/60 Hz) nominal

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Capacitance
Range1Accuracy2
100.0nF, 1000nF, 10.00µF, 100.0µF3) ±(3.5%+6 dgt)4
1)Accuracy below 50nF is not specified
2)Accuracies with film capacitor or better
3)Updates > 1 minute on large values
4)Specified with battery voltage above 2.8 V (half full battery). Accuracy decreases gradually to
12% at low battery warning voltage of approx. 2.4 V.
Resistance
Range1Accuracy2
600.0 Ω±(2.0%+6 dgt)
6.000 kΩ±(1.2%+6 dgt)
60.00 KΩ, 600.0 KΩ±(1.0%+4 dgt)
6.000 MΩ±(2.0%+4 dgt)
Open Circuit Voltage: 0.4VDC typical
1)AutoTectis for 6.000kΩ~ 6.000MΩranges;
2)Add 40 dgt to specified accuracy while reading is below 20% of range
Frequency
Range1Accuracy Specified At
10.00 Hz -30.00 kHz2< 2 0 V Sine-rms
10.00 Hz -999.9 Hz ±(0.5%+4 dgt) < 600 V Sine-rms
1Sensitivity (Sine-rms):
Hz in Auto-VΩposition:> 3 V
2Line-level Hz in V position
@ 6.000 V ac range: > 3 V
@ 60.00 V ac range: > 6 V
@ 600.0 V ac range: > 60 V

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DC µA Current
Range1Accuracy Burden Voltage
400.0 µA ±(1.5%+3 dgt) 6 mV/µA
2000 µA ±(1.2%+3 dgt) 6 mV/µA
AC µA Current
Range1Accuracy Burden Voltage
400.0 µA ±(2.0%+3 dgt) 6 mV/µA
2000 µA ±(1.5%+3 dgt) 6 mV/µA
Voltect
Typical Voltage Bar Graph Indication
20 V to 80 V -
45 V to 125 V - -
70 V to 215 V - - -
120 V to 285 V - - - -
above 170 V - - - - -
Indication: Bar graph segments & audible beep tones proportional to field strength
Detection Frequency: 50/60 Hz
Detection Antenna: Top left corner of the meter
Audible Continuity Tester (600 ΩRange)
Open Circuit Voltage: 0.4 V dc typical
Audible Threshold: >175 Ω±125 Ω
Diode Test
Test Current: 0.48 ma typical
Open Circuit Voltage: <1.6 V dc