OPERATION MANUAL OF DIGITAL LC METER
1. GENERAL DESCRIPTION
This 3 1/2 digital LC meter with high accuracy and uni t symbol display function is
driven by 9V battery. It has wide measurement ranges of inductance and capacitance.
With light-weight and compact structure, it’s widely applied in labs, production line,
maintenance locations and schools. LSI-circuit provides high reli ability and durability for
this meter. It can accurately measure capacitance of cables, switches, PCB circuit, etc.
It’s also an ideal tool for testing transformer winding, inductive choke, and induct ive
components. In addition, the meter offers advanced features, such as capacitor
self-discharge function. It can discharge the capacitor automatically, and protect the
meter from the damage caused by voltage. But if the voltage carried by the capacitor is
higher than 250V, please discharge the capacitor manually.
Please read this operation manual carefully before your operation!
2. CHARACTERISTICS
2.1 General characteristics
2.1.1 Display: LCD Max display 1999.
2.1.2 Inductance measurement: 1uH to 20H.
2.1.3 Capacitance measurement: 1pF to 2000uF
2.1.4 Calibration: Zero adjustment knob, can calibrate 20pF.
2.1.5 Over range: display “1”.
2.1.6 Low battery indicator: “
” symbol appears
2.1.7 Sampling time: 0~5seconds
2.1.8 Working conditions: 0℃ to 40℃, and relative humidity less than 80%
2.1.9 Meter size: 185mm×93mm×35mm (length × width × height)
2.1.10 Weight: about 290g (including battery)
2.1.11 Power source: 9V (6F22 or equivalent). Battery life: 150 hours for alkaline
battery, and 75 hours for carbon-zinc battery.
2.1.12 Standard Accessories: test alligator clips (red & black), and manual.
2.2 Technical data
Accuracy: ± (a% of reading+ digits) at 23 ± 5℃, relative humidity<75%.
2.2.1 Capacitance
Range Accuracy Resolution
2nF
±(2.0%+5)
1pF
20nF 10pF
200nF 100pF
2μF 1000pF
20μF 0.01μF
2000μF ±(5.0%+5) 1μF
2.2.2 Inductance
Range Accuracy Resolution
2mH
±(2.0%+5)
1uH
20mH 10uH
200mH 100uH
2H 1mH
20H ±(5.0%+5) 10mH
3. OPERATION
3.1 Panel description: (see the pic.1)
① LCD: display the measuring value, unit
symbol and low battery indicator.
② POWER key: turn On/Off the meter.
③ Zero adjustment knob/ “ADJ” knob: perform
zero adjustment before measuring capacitance
under 20nF.
④ Rotary switch: select measuring range.
⑤ Slot and jack: capacitance input terminal.
⑥ Battery door.
3.2 Cautions before measurement
3.2.1 To avoid false readings, which could lead to possible electric shock or personal
injury, replace the battery as soon as the battery indicator “
” appears.
3.2.2 To avoid damage to the meter or to the equipment under test, disconnect circuit
power source and discharge all high-voltage (higher than 250V) capacitors before
measurement.
3.2.3 Disconnect all the measuring
components before switching the function knob.
3.2.4 Capacitance measurement can’t be used to check the quality of the capacitor. It
may get a false reading when it measures the capacitance value of a resistor.
3.2.5 Pay attention to the polarity if the capacitor is a polarized type. Use the red test
clip to clip the capacitor’s positive and the black te st clip to clip the capacitor’s negative
when the capacitor has polarity.
3.2.6 DO not connect the test terminal with voltage source, and do not measure the
capacitor in circuit if there is high voltage. Even if it can get readings, it will cause the
big error and damage the meter (when the circuit is not powered off or there exists
voltage, or the capacitor isn’t discharged completely).
3.2.7 Do not short the test leads, otherwise it will cause dissipation of large current, and
make over range display in all ranges.
3.2.8 Zero adjustment will fail when SMD test clip’s capacitance is bigger than 20pF.
3.2.9 Inductance measurement can’t be used to check the quality of inductor. It may get
a false reading when it measures the inductance value of a resistor.
3.2.10 Do not measure the capacitor in circuit. Even if it can get readings, it will cause
the big error and damage the meter (when the circuit is not powered off or there exists
voltage.)
3.3 Capacitance measurement
3.3.1 Turn the rotary switch to a proper capacitance range;
3.3.2 To obtain accurate measuring values, perform zero adjustment before measuring
capacitance under 20nF. Slowly turn the “zero adjustment knob” to calibrate the display
until the LCD shows “000”. (Please perform the zero adjustment with test leads or SMD
test clip inserted in);
3.3.3 Insert the capacitor into the slot or clip the capacitor with test clip, the value will
be displayed on LCD with the unit of the selected range. If LCD displays “1”, it means
over range. If there is “1” or “00” before the digit, choose a lower range to increase the
resolution and accuracy.
Note:
1. If the value of capacitor to be measured is unknown, choose the lowest range 2nF and
increase the range step by step until a satisfactory reading is obtai ned and the over range
symbol “1” is disappeared.
2. If capacitor is breakdown, LCD will display over range symbol “1” in all ranges. If
capacitor has small leakage, LCD will display over range symbol “1” or a big
capacitance value which is much bigger than the normal value. If capacitor is
open-circuit, LCD will display “0” at all ranges;
3. When measuring the small (pF) capacitance, to minimize the effect of capacitance
stored in the test clips, the test clips should be as sho rt as possible and try to use the slot
if it is possible. Keep the test clips close to th e pins of capacitor under measuring, and
then perform zero adjustment. Make sure the distance between test clips isn’t change
when you measure the capacitor, thus can get an accurate value.
4. Some test leads may carry large capacitance, if it can’t be calibrated by “ADJ” knob,
you should remember the capacitance value, and then deduct it from your test results.
5. Some capacitors especially the electrolytic capacitor will have large capacity. Don’t be
surprised if the test result is much bigger than the nominal value. Usually the test result is
rarely smaller than the nominal value.
6. To check the existence of leaky capacitor, switch the function knob to different
capacitance ranges. If the test value has significant difference, it means there is a leaky
capacitor. The difference increases proportionately with the capacitance of leaky
capacitor.
3.4 Inductance measurement
3.4.1 Turn the rotary switch to a proper inductance range;
3.4.2 Insert the inductor into the slot or clip the inductor with test clip , the value will be
displayed on LCD with the unit of the selected range. If LCD displays “1”, it means over
range. If there is “1” or “00” before the digit, choose a lower range to increase the
resolution and accuracy.
Note:
1. If the value of inductor to be measured is unknown, choose th e lowest range 2mH and
increase the range step by step until a satisfactory reading is obtai ned and the over range
symbol “1” is disappeared.
2. To avoid extra induction, use the test leads as short as possible when measuring small
inductor.
3. Inductance measurement can’t be used to check the quality of inductor. It may get a
false reading when it measures the inductance value of a resistor;
4. AUTO POWER OFF
When there is no measurement in 20 minutes, the meter will auto power off and enter
dormancy mode. Press power button will exit the dormancy mode. It won’t power off
when LCD displays values bigger than 20% of the Max value at this range.
5.
MAINTENANCE
The meter is a precise instrument. Random changes to the circuit are not allowed.