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DC VOLTS TEST
1) If you have a variable power supply, set the supply to about the
midpoint of each of the DCV ranges and compare the kit meter
reading to a meter known accuracy.
2) If you do not have a variable power supply, make the following two
tests:
a) Set the range switch to 2V and measure the voltage across
the 100Ω resistor of Figure O. You should get about 820mV.
Compare the reading to a meter of known accuracy.
b) Set the range switch to 200mV and measure the voltage
across the 100Ω resistor of Figure P. You should get about
90mV. Compare the reading to a meter of known accuracy.
If any of these tests fail:
a) Recheck the meter calibration.
b) Check the value and the soldering of resistors R1 - R6, R10 - R12,
R14 - R17, VR1, and capacitor C4.
AC VOLTS TEST
To test the ACV ranges, we will need a source of AC
voltage. The AC power line is the most convenient.
CAUTION:
Be very careful when working with
120VAC. Be sure that the range switch is in the 200
or 600VAC position before connecting the test leads
to 120VAC.
1) Set the range to 200VAC and measure the AC
power line. The voltage should be about 120VAC.
Compare the reading to a meter of known
accuracy.
DC AMPS TEST
1) Set the range switch to 200μA and connect the
meter as in Figure Q. With R
current should be about 90μA. Compare the
reading to a known accurate meter.
123
10A DC
VΩmA
COM
Figure Q
equal to 100kΩ the
A
9V
R
A
Accurate
Meter
9V
9V
2) Set the range to 600VAC and measure the AC
power line. The voltage should be about 120VAC.
Compare the reading to a meter of known
accuracy.
If either if the above tests fail:
a) Check the values and the soldering of resistors
D1,R1-6 and R19.
b) Check that diode D1 is mounted as shown in the
assembly instructions.
2) Set the range switch and R
table. Read the currents shown and compare to a
known accurate meter.
Range Switch
2mA
20mA
200mA
If any of the above tests fail:
a) Check the fuse.
b) Check the value and soldering of resistors R7,
R8,R13,D2 and D3.
-9-
123
10A DC
VΩmA
1kΩ
COM
100Ω
Figure O
123
10A DC
VΩmA
10kΩ
COM
100Ω
Figure P
as in the following
A
R
Current (approx.)
A
10kΩ
900μA
1kΩ
9mA
470Ω
19mA
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