In general avometer
(multitester) has two roles active and passive role. By the time an active role
avometer will issue a voltage, otherwise at the time of the passive role
avometer will receive voltage. In this paper the author will explain the steps
of testing some electronic components such as resistor, capacitor, and
transistor by using avometer (multitester).
The general
characteristics of a avometer is a tool that is able to measure three
quantities, namely the strong current (A), voltage (V), and resistance (Ohm),
but it also has two poles: positive (red) and negative (black) pole. However,
please note that to use the positive pole barrier function measurements will be
black (+) and negative poles will be red (-). Multitester black probe is
connected to the positive polarity of the battery and the red probe multitester
connected with negative polarity battery inside the multitester.
Testing Resistor
will be used, because if
the limit measure used is not as it may damage the tool or component to be
measured. The pair limit measure suitable for testing the resistors are as
follows:
Although the resistor has a color
which aims to recognize the value of the resistance but to determine whether or
not the code can be tested using multitester. The function of the resistor are:
As a current divider, as lowering the voltage, as a voltage divider, as
inhibiting the flow of electric current, and others.
The steps of testing resistor are:
1. Choose
the size limit OHM-meter on the position within the limits of measurement, then
the end of the positive cable (red) end of the cable connected to the negative
(black) and turn the zero adjustment right needle indicates zero Ohm. If the
needle has shown 0 Ohm then deliver both ends of the cable.
2. Connect
the terminal resistor with Ohm-meter tester. When the pointer indicates the
corresponding value of the resistor color code the resistor otherwise still
good, if it does not mean the resistor damaged and if the needle does not move
then resistor is dropping.
3. When
we test resistor and it has a great value, we must choose a measuring scale
limit Ohmmeter larger or large multiplier. After that proceed to calibrate such
as step 1 and then testing can be resumed.
For example, we will examine whether
or not a resistor with color rings as follows:
Conclusion:
The
measurement results showed that the resistance value is so far away from the
resistance value of the resistor code listed. This shows that the resistor is
not good anymore because it has passed the maximum value should be.
Then how resistors are said still fit
for using? or in this case is still good and work according to its function ?.
Consider the following!
A resistor with a
resistance value as follows:
Based on
the measurement results in the table above shows that the value was not
significant between the resistance value based on the theory and measurement.
It can be concluded that the resistor can still work in according to its
function (good).
Testing
Capacitor
Similarly, the test
resistor, before testing a capacitor we need to first understand the limits of
the appropriate measure. Consider the following table!
The
testing capacitor steps are as follows:
1. Selector
switch from Ohm-meter placed at position x 10. Then the end of the positive and
negative wires connected on each leg of the capacitor.
2. When
the needle deviated and return to the original position means that the
capacitor is in good condition. When the needle is distorted and does not
return to its original position means capacitors leak and if the needle does
not deviate at all mean the capacitor is damaged (broken off).
Testing
Transistor
As we
understand that a transistor is a combination of two diodes. However, the
transistor itself has a kind are PNP (positive-negative-positive) and NPN
(negative-positive-negative). Before testing a transistor is very important to
understand the working principle of a transistor. So the working principle of a
transistor is like a forward biased diode. Suppose that in the forward
direction (forward bias), the positive pole of a diode is connected to the
negative pole avometer (black), and the negative pole of a diode is connected
to the positive pole avometer (red).
The
steps in testing a transistor are as follows:
1. For
the PNP transistor base must be connected to the positive end of the cable
while the end of negative cable are connected with the emitter and collector.
2. The
needle should deviates but if it only deviates when the cable end is connected
to the emitter or collector's foot only, the transistor is damaged. So both of
these conditions should cause the needle to deviates.
3. For
the NPN transistor polarity as when testing the PNP but beyond that the base is
connected to the negative end of the cable while the positive end of the cable
connected to the foot of the emitter to the collector. The needle should
diverge when the positive end is connected to the foot of the emitter and
collector. If only one deviating means transistors in a state of disrepair.
For
more details see the following table!
Conclusion:
If the
testing process are not in accordance with the rules of the table above it can
be concluded that the transistor is in a state of disrepair.