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Also, digital meters have a small margin of error due to the
fact that they run on a battery and are solid state. Digitals are generally
easier to use by the novice, and most of them have automatic range so you don't
have to worry about setting the meter for the correct ranges. Here is a photo of
a basic digital multimeter and the scale ranges.
|
Scale |
Measurement Range |
| in words |
ohms (Ω) |
| 2M |
two megohm
two million ohms |
0-2,000,000 |
| 200K |
two hundred
kilohm
two hundred thousand ohms |
0-200,000 |
| 20K |
twenty kilohm
twenty thousand ohms |
0-20,000 |
| 2K |
two kilohm
two thousand ohms |
0-2,000 |
| 200 |
two hundred ohm |
0-200 |
How to use a
digital multimeter.
DC (Direct Current) position: This
position is used to test DC circuits and components like batteries. With DC
voltage, you will put the red meter lead on the positive side of the component
being tested, and the black lead on the negative (ground).
AC (Alternating Current) position:
This position is used to test AC circuits like wall outlets and light sockets.
When testing an AC circuit, it doesn't matter what lead you put on what side of
the component being tested.
Ohms (resistance) position: This
position is used to check the resistance of a circuit or component. Again, with
Ohms, it doesn't matter what lead goes on which side of the component, unless
you are checking diodes.
DC mA position: This position is
used to test small amounts of DC current, you would hook up your meter leads
like you would for testing DC voltage.
hFE (transistor) position: This
position is used to test NPN/LED and PNP
transistors. I prefer to use the diode position when testing transistors,
but one feature this setting has is the holes to plug in the transistor/LED
directly into the meter. Watch this video for a demo.
http://www.youtube.com/watch?v=CbCOUrRrDH4
Analog
Analog multimeters have multiple scales on
the glass display, a moving needle and many settings on the function switch.
It’s sometimes difficult finding the correct scale to read on the dial, plus
you sometimes have to multiply the reading by 10 or 100 to get your final
value. The meters start out around $15US and can also go up into the
hundreds. Here is a photo of an analog meter.
How to use an
analog multimeter.
Using an analog meter is
almost the same as a digital, except for the display is
obviously different. For this reason, I will just say, that when
using an analog meter, be sure to always zero out the meter
before taking any reading. To do this, put your meter to the
Ohms setting, touch the two leads together, and use the "zero
out" knob to bring the needle to zero Ohms. Now the meter is
ready to use.
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