Elenco Electronics M-1150K, Сборка и инструкция по эксплуатации

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AC Voltage Test
In reading AC voltage, it is necessary to obtain a known source of AC. A 12 volt transformer is preferred.
If one is not available, use the 120VAC line.
CAUTION: Be very careful when working with 120VAC. Be sure that the range switch is in the 250 or
1000VAC position before connecting the test leads to 120VAC.
1) Plug the red test lead into the + socket, and the black lead into the -COM socket.
2) Set the range switch to the appropriate ACV position. Touch the test leads to the power source and
observe the meter reading. Then, multiply by the appropriate scale factor.
DC Current Test
The DC current circuit is protected by a 0.5 amp fuse. Be sure that the test current is below this level.
Obtain a 68K
Ω
resistor and a 1.5 volt battery (you may again use one of the 1.5V meter batteries).
Proceed as follows:
1) Plug the red test lead into the + socket and the black lead into the -COM socket.
2) Set the range switch to the 50
µ
ADC position.
3) Connect the 68K
Ω
resistor to the positive side of the battery. Connect the red test lead to the other side
of the resistor. Connect the black test lead to the negative side of the battery. The meter should read
about 22 on the 0-50 scale. This converts directly to 22
µ
A.
4) Set the range switch to the 2.5mADC position. Repeat step 3 using a 1K
Ω
resistor. The meter should
read about 150 on the 0-250 scale. Move the decimal point two places to the left to obtain 1.5mADC.
5) Check the remaining scales using a power supply and suitable resistors.
6) See Calibration Section for 10 amp range.
h
FE
Test
The h
FE
of a transistor is read using the two small test leads. One is a single lead with a single black alli-
gator clip and the other is a double lead with two wires, one with a red and the other with a black alligator
clip. There is a 24K
Ω
resistor in series with the black wire on the double test lead. To measure the h
FE
(beta)
of an NPN transistor, proceed as follows.
1) Plug the double test lead into the --COM socket and the single test lead into the + socket.
2) If you removed the 1.5 volt battery from the multimeter, replace it now.
3) Set the range switch to the ohms X10 position.
4) Connect the single test lead to the red wire of the double test lead and adjust the
Ω
ADJ pot for a zero
reading on the ohms scale.
5) Connect the single test lead to the emitter of the transistor.
6) Connect the red lead of the double test lead to the collector and the black lead to the base of the tran-
sistor.
7) Read the h
FE
of the transistor on the blue h
FE
scale immediately below the red ACV scale.
8) To measure a PNP transistor, connect the transistor to the test leads in the same way, but reverse the
test leads at the meter. That is, plug the single lead into the -COM socket and the double lead into the
+ socket.
Transistor Leakage Current Test
Leakage current is read on the Iceo scale. For small geranium transistors, set the range switch to 15mA
(the blue marking under the X10 ohms position). For large geranium transistors, set the range switch to
150mA. For silicon transistors, the leakage is usually too small to read. Read the leakage current as fol-
lows:
1) Plug the red test lead into the + socket and the black lead into the --COM socket.
2) Set the range switch to 15mA or 150mA.
3) Short the test leads together and adjust the
Ω
ADJ pot for a zero reading on the ohms (top) scale.
4) For an NPN transistor, connect the red test leads to the emitter and the black test lead to the collector.
For PNP transistors, connect the red test lead to the collector and the black lead to the emitter.
5) Read the leakage current on the Iceo scale. If you are on the 150mA scale, move the decimal point one
place to the right.
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