A "quickie" on how to use your multimeter...
(BTW, I don't own a "AC Voltage Detector" and would not use one except for maybe finding wires in walls. These can give misleading results. Indicate power is present when in fact the breaker is turned off.)
For the meter, you would place the test leads in the center hole (black) and the right hole (red). These are used for measuring everything you would use the multimeter for.
A bit about electricity...
Homes have what is called AC electricity or alternating current. The electricity switches back and forth many times a second. + -, then - +, then + -, etc. 60 times a second!
Then cars and flashlights - things with batteries use DC electricity or direct current. This is always + -.
So when using a multimeter to test for electricity, you need to set the selector to the right kind of electricity. And the right range (larger number than the voltage).
So to measure DC voltage, you would set your selector to the VDC area. And if measuring the voltage on a 12 volt car battery, you would set the selector to the 20 volt range. This will measure up to 20 volts. So VDC and 20 for a car battery.
For an electrical outlet in a house, you would set the selector on the meter to the VAC area. And house electric outlets and lights are around 120 volts AC. So set the range to 200. So VAC 200 to measure the electricity for an outlet or light.
And something in a home like an electric range, electric water heater, or clothes dryer would be 240 volts AC. To measure that you would need to use a higher range than 200. So you would set the selector to VAC 600.
Then ohms is continuity basically. You can use this to see if two wires connect. Or to test a fuse like in the link above. Set this to the ohms 200 setting, then touch the two test leads together. You will get a reading of 0 or close to 0. This is all you need to know about ohms for now. Just set it to 200 to test for continuity.
Warning: The power MUST be off before using the meter set to ohms. If there is live electricity, it will fry your meter!
And if there is a light bulb in the circuit, the ohm meter or continuity tester will see this! Or if there is a switch in the works and the switch is on, this will be seen as well.
Example: Take an
extension cord which is not plugged into anything. Set the meter to ohms 200, then measure the two prongs on the plug. Should read nothing. Now plug a lamp which is turned on into the other end of the
extension cord (no electricity connected). Now again read the two prongs on the plug. You now get a reading! Turn off the switch on the light. Now no reading!
So you can disconnect all the wires on the outside light. And all the wires from the switch which is connected to this light. Then use a length of wire to connect to the black wire going to the light outside (speaker wire or whatever). And run this wire inside. Then test with ohms 200 from that wire to the wire at the switch box going to that light and get a reading!
You can tell which wire goes to that light.
And no other wires will give a reading in the switch box to that wire.
BUT! If you leave the light fixture and light bulb connected to that wire outside, this connects to the white neutral wire at the light. That white wire connects to every OTHER white neutral wire in the HOUSE!
So the "testing electricity" from the meter would travel from the black wire, through the light bulb, to the neutral, to other light fixtures, through their light bulbs and to their black wires, through their switches if they are turned on, then back through to several other black wires in the 4 gang switch box!
[In other words, it is necessary to disconnect the wires at both ends so you get a valid continuity test.]
Then on the multimeter is BAT. Use that to test batteries.
And last is ADC and AAC. Basically this is useless, don't ever set your meter to these. This would be like a direct short across the test leads. This measures "amperage" or how much electricity is "flowing" through a wire. You would need to cut a wire, then use the test leads to complete the circuit to make this measurement. And using the bottom right hole would only measure a tiny amount of electricity. Measure more than that and it will blow a fuse in the meter.
And the test lead hole on the left goes up to 10 amps, but this is NOTHING
compared with the amperage which is used in a home or in a car. Useless!
Home electrical circuits are 15 amps, 20 amps, 30 amps, etc.
Car electrical circuits these days are 15 amps, 20 amps, 35 amps. And it is common to have a 100 or 150 amp alternator!
So the electricity flowing in most circuits these days is much more than the capacity of your meter. Don't use the amperage setting. They make and AC/DC clamp meter which goes up to 600 amps and would be much more useful for that! Here is one...
http://www.amazon.com/gp/product/B00...&redirect=true
More on multimeters...
http://www.google.com/search?hl=en&s...=f&oq=&aqi=g10
Linear Mode
