Amprobe LCR55A Operating Manual

LCR55A

Inductance, Capacitance,
Resistance Meter

User Manual

• Bedienungshandbuch

• Manualdeuso

• Moded’emploi

200

2m

2m

FUSED

F

H

200mA MAX

HOLD

HmHH

h

FE

MAX

EBCE

nF FmF

k M

20 ADJ.

20m

200m

2

20

200

NPN

NPN

PNP

PNP

200p

2n

20n

200n

2

20

200

2000

20M

2M

200k

20k

2k

200

20

OFF

hFE

hFE

(Icec A)

(Icec A)

Cx
Lx

Hi(+)

Lo(-)

Rx

MAX 350V

FUSED

DISCHARGE CAPACITOR

BEFORE CONNECTING

Lx Cx

LCR55A

M.W.

LCR55A

3-1/2 digit LCD; decimal point, function and unit indicators

3-1/2 Digit LCD ; Dezimalpunkt, Funktions- und Einheitsanzeigen

LCD de 3-1/2 dígitos, punto decimal, indicadores de función y unidades

LCD 3-1/2 digits ; point décimal, indicateurs de fonctions et d'unités

Low Battery

Batterie entladen

Pila baja

Pile déchargée

Zero adjustment for

20

Ω range

Nullabgleich für

20Ω Bereich

Ajuste de cero para

escala de 20 Ω

Mise-à-zéro pour

calibre 20Ω

Display Hold

Anzeigesperre

Retención de
lectura

Maintien de
lecture

Max Reading Hold

Max Anzeigesperre

Retención de

lectura maxima

Maintien de lecture

maximale

Positive and negative inputs for resistance
and diode test

Positive und negative Eingänge für
Widerstandsmessung und Diodentest

Entradas positiva y negativa para medidas
de resistencia y prueba de diodos

Entrées positives et négatives pour measures
de résistance et test de diodes

Function/Range/Off

Selector

Funktion-/Bereich-

/Aus Schalter

Selector de

Función/Escala/Off

Sélecteur fonctions/

calibres/marche-

arrêt

Input terminals
for transistor test

Eingänge für
Transistortest

Terminales de
entrada para prueba
de transistors

Entrées pour test
de transistors

High (+) and Low (-) inputs for capacitance

and inductance measurement

Hoch (+) und Niedrig (-) Eingänge für

Kapazitäts- und Induktanzmessung

Entradas alta (+) y baja (-) para medidas de

capacidad e inductancia

Entrées haute (+) et basse (-) pour measures

de capacité et d'inductance

LCR55A

Inductance, Capacitance,
Resistance Meter

Operators Manual

• Bedienungsanleitung

• Manual de Instrucciones

• Manuel d’Utilisation

PN 1566247
©2007 Amprobe.
All rights reserved. Printed in Taiwan

English

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 above 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.

Inductance, Capacitance, Resistance Meter

Contents

Symbols ..............................................................................................................1

Warnings and Precautions ................................................................................1

Overload Indication ..........................................................................................2

Preparation for Use – Unpacking .....................................................................2

Measuring Procedures ......................................................................................2

Specifications .....................................................................................................4

Troubleshooting/Maintenance .........................................................................6

Repair .................................................................................................................7

Symbols

Battery



Double insulated



Fuse

Conforms to relevant Australian standards

Warnings and Precautions

• Do not exceed the maximum overload limits per function (see specifications)
nor the limits marked on the instrument itself.

• Exercise extreme caution when: measuring voltage >20V .

• Inspect 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 probe tips.

• Do not operate instrument in an explosive atmosphere.

• Clean instrument with mild detergent only.







Refer to the manual

Audible tone

Complies with EU
directives

1

OverloadIndication

Range overload is indicated by a “OL” in the display with all
other digits blanked. Overload indication is normal in the
OHMS range with open circuit or too high a resistance.

PreparationforUse–Unpacking

Your shipping carton should include the LCR55A, one test lead set (one black,
one red), one pair of alligator clips, one 9V battery (installed), one spare

0.1A/250V fuse (inside the case), one holster, a warranty card and this manual. If

any item is damaged or missing, return to the place of purchase for an exchange.

MeasuringProcedures

General Procedures

1. When connecting or disconnecting test leads to/from a circuit, always first
turn off power to device or circuit being tested and discharge all capacitors.

2. If the magnitude of a signal to be measured is not known, set selector switch
to highest range first and reduce until satisfactory reading is obtained.

3. Strictly observe the max input limits.

Resistance Measurement (Fig. -1-)

1. Turn off power to the resistance to be measured and discharge any
capacitors. Any voltage present during a resistance measurement will cause
inaccurate readings.

2. Connect red test lead to +Rx Input and black test lead to -Rx Input.

3. Set Function/Range Switch to the desired Ω position.

4. Connect test leads to resistance or circuit to be measured.

5. Read resistance value on Digital Display. Open circuits will be displayed as an
overload condition.

Note: On the 20Ω range, an adjustment potentiometer (ZERO ADJ.) allows you
to zero out the test lead resistance. Short test leads and adjust the knob until the
display reads zero.

Diode and Transister Test (Fig. -2-)

The diode test measures the voltage drop across the diode junction.

4. Connect the red test lead to the +Rx Input and the black test lead to the –Rx Input.

5. Set the Function/range switch to  or to  M.W. position (to test diodes
found in microwave ovens).

6. Apply probe tip of red lead to the anode and black lead to the cathode
of the diode. The meter’s display indicates the forward voltage drop
(approximately 0.7V for silicon diode or 0.4V for germanium diode). Meter
will display overload condition for an open diode.

7. Reverse test lead connections to the diode to perform a reverse bias test.
Overload indicates a good diode.

Note: Overload condition for both reverse and forward bias tests indicate an
open diode. A low voltage reading for both bias tests indicates a shorted diode.
If the diode is shunted by a resistor of 1000 ohms or less, it must be removed
from the circuit before taking the measurement. Bipolar transistor junctions may

2

be tested in the same manner described above.
Note: The test procedure of microwave oven diodes is identical to regular diodes

except forward voltage drop will be higher (3 or more volts) than standard
silicon diodes. LEDs may also be tested with the LCR55A in the M.W. position.

Continuity Test
The Continuity test checks electrical continuity between two contact points.

1. Set the Function/Range switch to .

2. Plug the black test lead into the –Rx jack and connect the test lead tip to one
of the contact points.

3. Plug the red test lead into the +Rx jack and connect its test lead point to the
other contact point. (See Figure 1 for connections).

4. The internal beeper emits a tone when resistance is less than approx. 30Ω.

Capacitance Mesurements (Fig. -3-)

1. Discharge all voltage from the capacitor (via a 20kΩ resistor) before
measuring its value.

2. Connect the red test lead to the HI(+) input and the black test lead to the
Lo(–) input.

3. Set the function/range switch to the capacitance range that gives the best
resolution.

4. Apply probe tips to the capacitor leads

5. Read the capacitance value on the display (you may have to wait a few
seconds until the capacitor is fully charged). If “OL” appears in the highest
range, the capacitor is too large to be measured.

Note: Small value capacitors can also be measured by inserting their leads
directly into the Cx/Lx slots in the meter.

Note:The capacitance range is protected by a 0.1A/250V fast blow fuse. If fuse
blows, replace with same (see Battery and Fuse Replacement).

Note: The LCR55A has a residual capacitance of approximately 6pF in the 200nF
range. When using the 200nF range, note the residual capacitance and subtract
this value from the measured value.

Inductance Measurement

1. Connect the red test lead to the HI(+) input and the black test lead to the
Lo(–) input.

2. Set the function/range switch to the inductance range that gives the best
resolution.

3. Apply probe tips to the inductor leads.

4. Read the inductance value on the display. If “OL” appears in the highest
range, the inductor is too large to be measured.

Note: Small value inductors can also be measured by inserting their leads directly
into the Cx/Lx slots in the meter.

Note: The inductance range is protected by a 0.1A/250V fast blow ceramic fuse. If
fuse blows, replace with same (see Battery and Fuse Replacement).

Transistor Gain Measurement
The Transistor must be out of circuit.

3

1. Set the Function/Range switch to the PNP(hFE) or NPN(hFE) position,
according to the type of transistor to be measured.

2. Plug the emitter, base and collector leads of the transistor into the correct
holes of test socket.

3. Read the hFE beta, (DC current gain) in the display.

Note: To measure the collector-emitter current, set the function/range switch to
the corresponding PNP(Icec µA) or NPN(Icec µA) position.

MAX Function
Push the MAX button to keep only the highest reading on the display. The
display is updated each time a higher value is encountered. Push MAX again to
release the display and to display current values.

Hold Function
Press the HOLD button to maintain a reading on the display. The reading is
maintained even when the probe tips are removed from the meter. Pushing the
HOLD button again releases the display.

Safety Test Leads
The test leads included with your meter have shrouded banana plugs to
eliminate the possibility of shock if the plugs accidentally pull out of the meter
while making a measurement. Always inspect the test leads for damage before
making any measurements.

Specications

General Specifications
Display: 3 1/2 digit LCD, 1999 counts, 0.7” (17.8mm) high numerals, unit

annunciators and function symbols

Polarity Indication: Automatic, positive implied, negative indicated
Zero Adjustment: Automatic
Overrange Indication: “OL”
Low Battery Indication:  is displayed when the battery voltage drops below

accurate operating level. Change battery immediately.

Display Update Rate: 2.5 per second, nominal
Operating Temperature: 0°C to 50°C, 0 to 70% Relative Humidity
Storage Temperature: -20°C to 60°C, 0 to 80% RH with battery removed
Temperature coefficient: 0.1 x (spec. accur.) per °C (0-18°C, 28-50°C)
Power: Standard 9-volt transistor battery, NEDA 1604, JIS 006P, IEC 6F22
Auto Power Off: 60 minutes after no function or range change
Battery Life (Typical): 30 hours alkaline (changes with function and application)
Dimensions (H x W x D): 18.3 x 7.9 x 3.8 cm, (7.2 x 3.1 x 1.5 inches)
Weight (including battery): 311 grams (11 ounces)
Accessories: Test leads, 0.1A/250V spare fuse, battery, one pair of alligator clips

and Operator’s Manual.

4

Agency Approvals:  EMC

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
precautions to avoid misleading results when making measurements in the
presence of electronic interference

Electrical Specifications

Accuracies at 23°C ± 5°C, <75% RH.

Resistance

Ranges: 20, 200Ω, 2, 20, 200kΩ, 2, 20MΩ
Resolution, 20Ω range: 10mΩ
Accuracy: 20Ω range: ±1.2% rdg (zero adjust)
200Ω range: ±0.5% rdg +3dgt
2k to 2MΩ rgs: ±(0.5% rdg +1dgt)
20MΩ rg: ±(2.0% rdg +2dgt)
OL Protection, all ranges: 350VDC or AC RMS
Open Circuit Voltage; 20Ω range: 6.5VDC; 200Ω range: 3.0VDC; other ranges:

1.2VDC

Continuity

Audible Indication, 2kΩ rg: at R ≤30Ω
Response time: 800ms approx
OL Protection: 350VDC or AC RMS

Diode Test

Test Current: 1mA (approx.)
Test Voltage: 3.0VDC typical
Accuracy: ±(1.5%rdg +1dgt)
Display: Forward Junction Voltage
OL Protection: 350VDC or AC RMS

Micro Wave Diode Test

Test Current: 1.3mA (approx.)
Test Voltage: 8.0VDC typical
Accuracy: ±(3.0%rdg +1dgt)
Display: Forward Junction Voltage

OL Protection: 350VDC or AC RMS

Capacitance

Ranges: 200pF, 2, 20, 200nF, 2, 20, 200, 2000µF
Accuracy*:200pF to 200nF: ±(1.0% rdg +3dgt)

2µF to 200µF rgs: ±(2.0% rdg +3dgt)
2000µF range: ≤1000µF ±(3.0% rdg +3dgt)

>1000µF ±(5.0% rdg +5dgt)

Note: In lower ranges, substract 6 points residual offset reading from result

Test Frequency: 200p to 2µF: 1000Hz; 20, 200µF ranges: 100Hz; 2000µF range:

10Hz

5

Temperature Coefficient: ≤0.5µF: 0.1%/°C; >0.5µF: 0.2%/°C
OL Protection: 0.1A/250V fast blow fuse.

Inductance

Ranges: 200µH, 2, 20, 200mH, 2, 20, 200H
Accuracy: 200µH rg: ±(5.0%rdg +30dgt)*
2 to 200mH: ±(3.0% +20dgt)*
2 to 200H: ±(5.0% +20dgt)*
*For values of Q ≤7
Test Frequency: 200µH to 2H rgs: 1000Hz; 20 and 200H ranges: 100Hz
Temperature Coefficient, ≤0.5H: 0.2%/°C; >0.5H: 0.5%/°C
OL Protection: 0.1A/250V fast blow fuse

Transistor Test

hFE Range: 0-1000
hFE Base Current: 5µA approx.
hFE Voltage C-E: 3.0VDC approx.
I

Range, Leakage Current: 10nA to 20µA

ceo

Optional Accessories

VC221B Vinyl Carrying Case (for meter and holster)
DL243D Standard Test Lead Set
DL248D Deluxe Test Lead Set
TL36A Replacement Test Leads with Alligator Clips

Troubleshooting/Maintenance

If there appears to be a malfunction during the operation of the meter, the
following steps should be performed in order to isolate the cause of the problem:

Check the battery.
Review the operating instructions for possible mistakes in operating procedure.
Inspect and test the Test Probes for a broken or intermittent connection.
Inspect and test the fuse. See Fuse Replacement.
Except for the replacement of the battery or fuse, repair of the multimeter

should be performed only by a Factory Authorized Service Center or by other
qualified instrument service personnel.

The front panel and case can be cleaned with a mild solution of detergent and
water. Apply sparingly with a soft cloth and allow to dry completely before using.

Battery/Fuse Replacement

To prevent electrical shock hazard, turn off the multimeter
and any device or circuit under test and disconnect the test
leads before removing the rear cover.

1. Remove the screws and lift off the rear case.

2. Fuse Replacement: Remove the blown fuse (5 x 20mm) from the fuse holder.
Replace with a 0.1A/250V quick acting glass fuse (one spare fuse is located on
the right side of the battery compartment). Amprobe replacement fuse part
number is FP 125.

3. Battery replacement: Remove battery and replace with NEDA type 1604 or
equivalent 9 volt alkaline battery.

4. Reassemble the instrument.

 Warning

6

Use of an incorrect fuse could result in serious injury or even
death. Failure to turn off the multimeter before installing
the battery could result in damage to instrument and battery.

 Warning

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 In­Warranty 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.

In USA In Canada
Amprobe Test Tools Amprobe Test Tools
1420 75th Street SW 400 Britannia Rd. E. Unit #1
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

In den Engematten 14
79286 Glottertal, Germany
Tel.: [phone] - 0
*(Correspondence only – no repair or replacement available from this address.
European customers please contact your distributor.)

7

200

2m

2m

FUSED

F

H

200mA MAX

HOLD

MAX

EBCE

20 ADJ.

20m

200m

2

20

200

NPN

NPN

PNP

PNP

200p

2n

20n

200n

2

20

200

2000

20M

2M

200k

20k

2k

200

20

OFF

hFE

hFE

(Icec A)

(Icec A)

Cx
Lx

Hi(+)

Lo(-)

Rx
MAX 350V

FUSED

DISCHARGE CAPACITOR

BEFORE CONNECTING

Lx Cx

LCR55A

M.W.

2

1

Cathode Anode

Cathode

600 - 900 mV

<1 V

Anode

3

2

4

OK

OK

OK

OK

200

2m

2m

FUSED

F

H

200mA MAX

HOLD

MAX

EBCE

k

20 ADJ.

20m

200m

2

20

200

NPN

NPN

PNP

PNP

200p

2n

20n

200n

2

20

200

2000

20M

2M

200k

20k

2k

200

20

OFF

hFE

hFE

(Icec A)

(Icec A)

Cx
Lx

Hi(+)

Lo(-)

Rx

MAX 350V

FUSED

DISCHARGE CAPACITOR

BEFORE CONNECTING

Lx Cx

LCR55A

M.W.

4

3

2

5

1

8

3

200

2m

2m

FUSED

F

H

200mA MAX

HOLD

MAX

EBCE

F

20 ADJ.

20m

200m

2

20

200

NPN

NPN

PNP

PNP

200p

2n

20n

200n

2

20

200

2000

20M

2M

200k

20k

2k

200

20

OFF

hFE

hFE

(Icec A)

(Icec A)

Cx
Lx

Hi(+)

Lo(-)

Rx

MAX 350V

FUSED

DISCHARGE CAPACITOR

BEFORE CONNECTING

Lx Cx

LCR55A

M.W.

3A

3B

1

2

4

9