Multimeters

Multimeters are sometime called multitesters, and they are some of the most useful and important measuring devices available. They are basically electronic measuring instruments that combine several functions into one unit. The most basic instruments that you will find in multimeters are an ammeter, a voltmeter, and an ohmmeter.

You can find digital, analog, and combo multimeters on the market today, and they are usually affordable. It might be helpful to note that analog multimeters are sometimes referred to as "volt-ohm-meters", abbreviated VOM. Digital multimeters are usually referred to as "digital-multi-meters", abbreviated DMM.

Multimeters can be small enough to be hand held or they can be of the bench type. The handheld multimeters are useful for basic fault finding and field service work. The bench types will usually measure to a higher degree of accuracy. Bench types are often found in a calibration lab and can be used to calibrate resistance and voltage standards or adjust and verify the performance of multi-function calibrators.

Low end, basic multimeters will be able to read current, voltage, and resistance measurements. These are considered the standard features for multimeters. You may, at some time, come across a device that is called an AVO multimeter. This was an early model of multimeters and they used the terms amperes, volts, and ohms, which are now more commonly known as current, voltage, and resistance.

Multimeters are considered standard tools for both electricians and those interested in electronics. As such, they come in a wide range of models and in a wide range of prices. Less complex units can easily be found for around $20 or so. More complex models can run into the high-hundreds of dollars. There are many excellent models that can perform various tests in the hundred dollar range.

While multimeters are very important in commercial work, they are also very handy to have around the house or garage. They can be used to test just about any type of circuit and they can also help run down problems.

Analog multimeters are not hard to find but they are becoming less common than digital units. It should be noted that many people consider the analog multimeters to be less accurate, although some of this can be attributed to eyesight rather than to the unit. Any errors introduced in zeroing the unit will result in inaccurate readings. This is usually less of a problem with the digital units.

You should also know that analog meters may use vacuum tubes to precondition and amplify the input signal. Such meters are known as vacuum tube volt meters (VTVM) or vacuum tube multimeters (VTMM). These types of multimeters can be expensive to repair; something to keep in mind before buying one.