By J Cosmos 
J Cosmos
Level: Basic PLUS
Write me at jimmycosmos@yahoo.co I am not a tycoon. I am not the president of the railroad. I am an observer who sees humanity coming …
People interested in residential power generation products need the assistance of simple, but accurate measuring devices. The use of photovoltaic or wind energy is entirely dependent upon your ability to measure accurately. I recently wrote a piece where I suggested to people who were unfamiliar with a multi-meter to just go to Radio Shack and ask the clerk how to do it. I was wrong to blithely say that. If you are unfamiliar with the machine, you need a little more in order to complete accurate work, and accurate work is the hallmark of a good job well done. If you are considering an alternative energy resource, then you need to prepare yourself with some basic skills, and a multi-meter is one of the most essential. Let’s talk a little basic material about the machines and then I will refer you to some free sites where you can further your education. Keep in mind that this machine is used to check for AC or DC voltages, resistance or continuity of electrical components and small amounts of current in circuits. You can use this meter to see if there is voltage present in a circuit. The meter I am looking at is a analog, so let’s talk about it. While some manufacturers have some differences, they do similar functions and we should be able to hit the main parts. First, let’s talk a bit about the components you will find:
As you pick the meter up, the first thing that will strike you is the dial. On my analog machine, it has an arc shaped scale visible through a window. The pointer will indicate values of what you are measuring.The needle (or pointer) I just mentioned. It is usually a black line in the window which moves to the value you are measuring.The arc shaped scales on the meter dial face. You might find different colors for each scale but with different values. These will show the range of magnitude.You may find a mirror like surface to reduce parallax viewing error. It will do this by lining up the pointer with its reflection before you read the value. If I confused you, it often looks like a wide gray strip between the red and black scales.Note the selector switch or knob. This allows you to change the functions between volts, ohms, amps, as well as the scale (example: x1,x10,etc.) of the meter. If you look carefully, you will see that many of the functions have multiple ranges. This is most important! Both need to be set correctly to prevent damage to either the meter or yourself. Be sure and set the switch to off when storing the meter.Note the jacks, which are openings in the case that you will use to insert the test leads. On most meters you will find several. Some just have two. It is vitally important to have the test leads connected to the proper jacks. All must be correct. Consult your manual and make this familiar. It is not rocket science but it is most important.See the test leads. There should be two leads (or probes) and you will find one to be black and the other to be red.Look on the side or back and find the battery and fuse compartment. You will find the fuse there (and possible a spare fuse) The meter may contain more than one battery and possibly different sizes. A good fuse is not helpful. It is essential. Keep a spare. Fully charged batteries are essential for resistance/continuity tests.Look carefully and find a small knob, usually it is near the dial and is labeled “Ohms Adjust,” “0Adj,” or similar. You will use this only when the in the ohms or resistance range while the probes are crossed and touching each other. Move the knob slowly to work the needle to the 0. A needle that will not do this indicates weak batteries.Let me now include a few sources where you can get an accurate idea how to operate one of these machines. Keeping in mind that a home energy audit is essential to any alternative energy power generation program http://mechatronics.mech.northwestern.edu/design_ref/tools/multimeter.html These are some great resources and you can learn a lot from them. There are dozens more. Watch, experiment and learn. Be SAFE. No exceptions. Do Good.
Article Submitted On: November 12, 2010
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