SO, I HAVE MY VERY FIRST MULTI-METER, JUST WHAT - CAN - IT DO-??

-- a basic primer for anyone new to the area of electrical testing and digital multi-meters.

AC VOLTAGE: Alternating Current. This encompasses almost everything electrical both built into your house, its systems, its wiring and all electrical devices that plug into that wiring, many home electrical items can be tested. Be cautious of AC electricity - its dangerous if not respected. Be sure to read up on proper and safe testing methods, again a trusted internet or other knowledgeable source is invaluable here. You can check circuits, circuit breakers, lighting fixtures, components on small and large home appliances of all kinds when armed with the right knowledge and a decent multi-meter. The AC range will usually be shown as a single wavy line on your meters range selector or it may just be marked AC. Learn safety first and know what youre doing, its best for the layman to stay clear of high voltages if he isnt well versed in that area - again, safety first.

DC VOLTAGE: Direct Current. This encompasses endless types of portable devices and batteries of all kinds, your riding mower or most anything in your cars 12 volt DC electrical wiring, the battery, connections, faults in interior switches and controls, lighting, solenoids, fan motor, harnesses etc. You can also do a quick check of your cars resting battery voltage while the engine is off, or the charging system and its alternator can be given a rudimentary check while the engine is running to see if the alternator is charging. There are some exceptions in todays modern computerized cars, some alternators are now controlled by the cars computer to reduce parasitic engine loads and increase gas mileage, so be wary of false readings here. You can also do a parasitic draw test to see if you have something draining your cars battery overnight, this can be hard to find but not impossible. The parasitic draw test will not work on your brother in law - that requires a completely different tool outside the scope of this article. All the information to test anything automotive can be found in repair manuals or on the internet where a plethora of car repair videos exist, but choose any video tutorial wisely - for certain types a little knowledge is a dangerous situation resulting in police, fire engines and possibly spending time with a cheap lawyer. DC current is everywhere in our lives, everything from flashlights to cell phones, your wifes marital aid and laptops run on DC. Wall-wart adapter transformers of all kinds used to change AC wall voltage to DC or step it down to lower AC voltages for low power devices can be tested for proper voltage output, read the transformers sticker to find its correct AC or DC output. Unlike AC current DC current is polarized, that is to say there's always a positive and negative terminal with a few special exceptions - excluding the new couple that just moved in next door . The DC range on your meter is often shown with two lines beside each other, one solid the other dotted, or again on some meters it may simply be marked DC.

CONTINUITY: The continuity test is as simple as an on off switch, its an audible go / no-go test that's one of the oldest and most useful test ranges of a multi-meter. Basically its a simple resistance test but instead of a digital readout you simply listen for the "beep" that says your circuit, wire or connection is good - no beep no good. Just touch your leads to either end of a circuit, fuse or anything supposed to be conductive, if you get the "beep" the connection - or continuity - is good, again no beep no good you have a break or bad connection in the circuit somewhere. One thing, be sure the circuit is OFF and not energized or you may become an unwilling part of said circuit. Continuity is usually shown on your range selector as three or four graduated lines resembling a speaker or speakers output.

RESISTANCE or OHMS: Same basic test as continuity but instead of a simple beep this test is ranged and measured in OHMS, it looks for a specific reading to indicate how much resistance is in a line, circuit, connection, circuit board device or component such as resistors, which are also used in your meter itself. High resistance in a cars wiring often indicates a bad or corroded connector as an example - a good circuit would have a certain low or no ohms reading, a bad circuit would have an abnormally high reading or even infinite, this would be the same as bad continuity. The OHMS symbol on your meter looks very much like a horse shoe, nothing else on the meter looks like it. One thing, dont believe the hype - resistance is not futile.

CAPACITANCE: This range is for testing electrical components called capacitors, these are electrical storage components used in devices and circuits of all kinds, audio visual equipment use capacitors, your meter itself uses capacitors -- many appliances, central air conditioning etc. use large capacitors to help start the motors and compressors - many electrical devices in fact pretty much anything with a circuit board that we use every day will have capacitors in a large variety of types and sizes from extremely tiny to very large, some are polarized some are not depending on markings, think of them as a different type of quick release storage battery but meant for electrical circuits - some capacitors are also used as filters in circuit boards, they have a huge range of uses. The capacitance symbol on your meters range dial looks like two letter T's laying on their side facing each other. NEVER test a capacitor in a live circuit, and ALWAYS be sure a capacitor is discharged before testing, again read up on it and know what youre doing. In many instances a capacitor can be discharged for testing by shorting its leads, but a capacitor of any size can really pack a major wollop, really big ones can kill you so be sure you know whats what before testing large caps and know how to discharge them safely, especially the larger ones. Its not a 9 volt battery so do not use your tongue - no matter how well calibrated you think it may be.

DIODE TEST: A diode is a one way voltage control component that allows a calibrated amount of voltage to travel in one direction only but not in the other. Diodes come in a wide range of types and sizes and are found in all manner of electrical devices. A basic test of a simple diode can be conducted out of circuit by measuring its DC value, but only in one direction - tested in one direction you should get nothing, in the other you would get whats known as the diodes "forward voltage" value, this is the diode test result. The diode symbol looks like a sideways arrow with a line in front of it. A very few meters also have an LED test range, LED's are a type of lighted diode but its functions are more visual than value based. The LED test range is currently only found on small number of meters though a few select meter diode ranges will test LED's for value and light them as well.

MILLI-VOLTS: A milli-volt is one thousandth of a volt either AC or DC, but most commonly used in DC measurements - its most commonly shown on the range dial as "mV". This range is used in small devices of many kinds and in all types of circuit boards, heating and cooling thermostats or other various low voltage control devices such as medical equipment can also use mV - do not attempt to test your aunt Sophies pacemaker, its bad form. Depending on the meter it may or may not require switching to a different mV range on the range selector - some lower cost or specific purpose multi-meters only read milli-volts on the main volt range and have no separate mV range setting, a few low cost meters may not read millivolts at all or not read them reliably. If you need this range specifically choose a meter accordingly.

MICRO-VOLTS: A micro-volt is one millionth of a volt either AC or DC but more often DC. This very low resolution is the most specialized and smallest range of the volts measurement and lower than an everyday user is ever likely to encounter - if at all - but it can be found in hobby electronics. Micro-volts are used in low voltage circuit boards and very specialized control or monitoring devices such as but not limited to thermo-couples used to read temperature in things such as furnaces and water heaters, micro-volts are usually displayed on your range selector as "uV". Many meters have a temperature range that uses an external thermal probe, it usually runs on micro-volts. Your meter may or may not have a specific micro-volt range on the dial. It takes a reasonably good quality meter to read microvolts reliably enough to be trusted in critical areas like circuit board work or in such critical areas as medical equipment.

AMPS: Also known as "Current" which is measured in amps is usually shown with an "A" on the range dial, voltage and amperage are measured differently and require a bit more knowledge and care, seek reliable information in your manual or on the internet for ways to properly connect and measure amps as high amperage draws can be dangerous to you and your meter and if you go above the meters maximum amperage rating - usually 10 amps or so - there is usually an AMP fuse in the meter itself, but depending on what youre doing and if the meter is correctly fused or things can heat up and get out of control pretty quick. Measuring amps is done on a separate range of your meter and a jack change of the positive lead is necessary to the "A" range, be certain you know what youre doing when measuring amperage.

MILLI-AMPS: A milli-amp is one thousandth of an amp, shown on your range switch as "mA". As you may have guessed its the next range down from amps. This range is also found mainly in small control circuits and circuit boards of all kinds and hobby electronics. The mA range is also fused at a much smaller limit usually from around 200mA to around 400 or 800mA, use care not to exceed the meters limit and blow these fuses they can be very hard to find locally. Also DO NOT use a fuse larger than the fuse rating specified by the meter or its manual - you can easily blow out the milli-amp range in your meter, and a new fuse wont fix this. Micro-amps are usually measured from the same positive jack as volts or milliamps, but check your individual meter.

MICRO-AMPS: A micro-amp is one millionth of an amp, usually shown your range selector as "uA". Reserved for the smallest and lowest amperage's in areas like circuit boards and specialized control devices and circuits. It takes a reasonably good quality meter to measure micro-amps reliably, you can also find micro-amps used in hobby electronics. Micro-amps are usually measured from the same positive jack as volts but again check your particular meter.

FREQUENCY: Usually marked as "Hz", or "Hz/%" if the meter reads both frequency and duty cycle, frequency is often used in AC work or oscilloscope testing, not every meter will have this range, but many do. An easy example of reading frequency would be AC wall voltage. In many meters while reading the AC wall voltage in your home, usually around 120 volts - you can push a button marked "Hz" and in areas like the U.S. you should see a reading of 60Hz, normally the frequency is half the voltage reading - if it deviates much at all from this reading something may be wrong with your line voltage and you might want to call your local power company and ask why, there could be problems with a local service transformer or at the power company itself. If your meter also has the "%" as well as "Hz" range your meter also reads whats called "duty cycle", in U.S. AC service this should read right at 50%, this is because unlike DC voltage that usually runs in one direction AC voltage cycles in both directions and the native value of this AC cycle is normally 50% based on 120 volt line voltage. Frequency is used in many other areas as well such as radio and TV transmission and many other areas, circuit board repairs often involve frequency based components.

TEMPERATURE: Often shown as C*/F* on the range selector. Obviously youre reading how hot or cold something is, a few meters may read ambient air temperature just by turning to the C*/F* range and selecting either Celsius or Fahrenheit either on the range switch or with a button and the meter will read room temperature. But the more often used method is to turn your selector to the temp range and insert a temperature probe that comes with your meter, it may go in the + and - jacks, or it may be a blade style connector that uses an adapter to match it to the plus and minus jacks of the meter, all meters vary in this regard. The temperature range can be used in many areas, most common is in measuring the air temps in HVAC heating and cooling systems in both cars and homes. HVAC repair technicians use this range almost every day in their line of work. Also know the probe requires time to settle and arrive at its final reading. As an exercise you can also use your temp probe to check soldering iron tip temperature, but checking your BBQ grill or neighborhood bonfire is -not- recommended.

SELECTOR BUTTONS: Youre meter will likely have some array of buttons located just above the range switch, these include RANGE, basically a change of the decimal point on the display to gain the needed readout. Also MAX.MIN or one of these individually depending on the meter, as it says you can set the meter to read a maximum or minimum value and hold it for later evaluation. The "Hz" or frequency button may be located here, as well as a SELECT button - this ones a biggie - it usually toggles between three or four main ranges and it will be marked accordingly using various ranges discussed above, or on some meters it only shown with single color. There will also be a HOLD button, on most meters this simply freezes the display reading at the time. More advanced meters take this a step further and after you turn HOLD on the meter will lock the displayed value as soon as you take a measurement with the probes, a handy feature that leaves both hands free for the work while not in view of the meters display so it can still be viewed after you extricate yourself from whatever inconvenient location you may be in while taking the reading.

BACKLIGHT: Another obvious one - usually a push on / push off button depending on the meter. Backlights light your digital display and they usually time out and shut off after around 15 to 45 seconds - this is officially the most hated and frustrating quirk of most any multi-meter ostensibly used to save battery life, though much flack has been voiced about it over the years and manufacturers are only now starting to implement longer backlight times and a scarce few now even let you leave it on perpetually, a most popular feature if your lucky enough to have a meter with it. Some meters also have a novel auto-backlight feature that uses a photocell causing the light to come on automatically based on how dark the environment is - the problem with this idea is its usually not selectible for degree of darkness, and on most meters with this option the light only comes on when its very near dark, leaving you in the dark in shaded or low light situations, just as bad as the light turning off when you need it most.

MISTAKES TO AVOID: Three of the worst and most common mistakes made with multi-meters are to forget to remove connected leads before changing ranges or similarly connecting the leads with the wrong range pre-selected, or changing ranges while the meter is connected to voltage. At the very least you can blow a fuse or brick the meter permanently, at the worst it could be your first foray into the thrill of handheld fireworks and gaining a really wild hair style that may or may not need extinguishing - though it may be popular with certain members of the "Avant gard". If things go even worse you'll never know about any of the above making the whole thing a moot point. Learn proper procedure and respect for what electricity can do, this is a must.

VALUABLE ADVICE: This covers the main test ranges of digital multi-meters, there are more specialized and advanced ranges and features on higher end meters - but these are usually beyond the

need of a first time multi-meter owner. One bit of advice for those going beyond light duty use, if you plan on owning and using your multi-meter in your main job involving serious voltages and currents or any long term use and it will be the only meter you purchase, buy the highest quality most suitable meter you can possibly afford for the given use. There's a BIG difference in a hobby or D.I.Y. meter and a meter used in serious multi-phase electrical work - if you're buying a meter for use with high voltages in seriously dangerous environments such as that of an electrician, manufacturing facility, power plant or other high current environs then DEFINITELY buy a high end name brand meter with all the built in protections and safeguards suited to its intended use. Investigate the meters CAT ratings and read up on their levels of application for help in selecting a suitable meter. Such meters are not cheap, but in these scenarios your life is on the line every time you enter this kind of environment so get as much advice from professionals in the field and anyone else you trust.

One important thing, and it should be obvious - WATER AND ELECTRICITY DONT MIX. One might think "hey, everybody knows this" - but you'd be surprised how many times someone not realizing has stood in a puddle of water in a basement using a multi-meter maybe not even having the presence of mind to realize it. working around leaking plumbing is a good example, be aware of your environment at all times.

THE GOOD NEWS: Not only is a multimeter useful for home and other repair tasks, if you are planning on entering the realm of hobby electronics it can be very fun and satisfying, this usually involves low voltages and there is a huge amount of low cost arduino and other types of hobby electronics componentry available today to build all manner of circuits, devices and even radio controlled models. Never before has so much affordable hardware been available to the average and often young electronics hobbyist. Couple the massive amount of knowledge available on the internet with your new meter and there's almost nothing you cant learn to fix or build. This kind of hobby can start out very inexpensive and if interest grows it can even evolve into a secure lifetime career working in electronics, and who doesn't want a secure career these days-? Better yet there will always be a need for qualified technicians in all manner of jobs and if you enjoyed electronics as a hobby the old addage applies - "if you find a job you like you'll never work a day in your life". Im no technician for sure, but I say learn as much as you can as soon as you can, then keep on learning - knowledge is a very powerful tool in life and in many vocations, the more you learn the more you earn and the more you know the more you grow.