How To Use A Multimeter To Test

Hi Nelson,

I checked the specs of your meter. First it is a CAT III meter with ETL and CE certifications. However it is a manual meter, i.e you have to select the appropriate ranges for each function. It does not measure current, but does measure resistance. There is a caution to make sure that the circuit is not energized when using the resistance function and that capacitors must be discharged. It warns that selecting the incorrect function can cause internal damage and it is not repairable.

There is no mention of an internal fuse, so I assume it doesn't have one. For run of the mill ac / dc voltage and resistance measurements I don't see anything wrong with it.

I have a number of good meters but usually just use my cheapie for most stuff.

David

chips&more said:

For me personally, I would only want a Fluke brand mulitimeter. ... ... Do not get the older all gray cased models. And only get it with the original Fluke probes/wires (that have not been spark tested)…Good Luck, Dave

Click to expand...

What is the issue with the older all gray cased models? I purchased a tool box a while back that came with a 'free' Fluke 73 Series II Multimeter with new Klein probes (among other things). I realize free test equipment is worth what you paid for it until proven otherwise, but is there a specific reason for concern?

Everyone has their favorites. I'm partial to Simpson 260's. In electronics work, digital meters can waste time, especially when adjusting a circuit to read a specific voltage or current. Not much need to do that in electrician type work, though.

chips&more said:

For me personally, I would only want a Fluke brand mulitimeter.

Click to expand...

I am partial to Fluke equipment as well. BUT..........as with any product, they can have their issues too. I was involved in a "root cause" investigation of a serious arc flash accident while using a Fluke 87. As with most of these type of accidents, it was first "assumed" that the cause was likely human error. Ultimately, it was determined by our electrical lab that there was in fact a defect in the meter. By the way, this investigation also involved Fluke technical staff as well. So, my point is that even the best can occasionally have a bad apple.

Ted

talvare said:

I am partial to Fluke equipment as well. BUT..........as with any product, they can have their issues too. I was involved in a "root cause" investigation of a serious arc flash accident while using a Fluke 87. As with most of these type of accidents, it was first "assumed" that the cause was likely human error. Ultimately, it was determined by our electrical lab that there was in fact a defect in the meter. By the way, this investigation also involved Fluke technical staff as well. So, my point is that even the best can occasionally have a bad apple.

Ted

Click to expand...

Hi Ted, that’s interesting? Don’t recollect ever noticing any recall on the 87’s? And yes, nothing is perfect or made to last forever! Some of the buyer’s on fleabay seem to think so though…Dave

Ohm's law will give you the understanding to be able to operate a Volt-Ohm Meter properly and safely. Once one
experiences the relationship between volts, current and ohms, a test meter will no longer be a mystery. The ohms
law formula is I=E/R where I is current in amperes. is electromotive force also known as volts, and R which is
resistance in ohms. Another way to look at the formula is R=E/I or E=IR. Knowing this formula allows one to solve the
equation for the missing piece of information. Let's say for example you have a 1.5 volt D cell battery and a flashlight
light bulb of 10 ohms and you want to know how much current will flow through the circuit. 1.5 volts divided by
10 ohms would be .15 amperes(150 milliamperes). If you actually do this, the initial current will be .15 amperes
and as the filament heats up, the resistance will increase and the current will drop somewhat in direct relationship to
Ohm's Law. Generally one will pretty much know the answer before verifying with the test meter and use the
meter as a verification rather than just a meter reading. Personally I like an analog meter for general use as
it provides a quantitative reading on a scale rather than just a digital reading. After a bit of experimentation,
one will be able to comfortably use a VOM (volt-ohm-meter) with confidence. You will know to use the ohms
scale for testing continuity or resistance. You will know to turn the meter scale to AC volts ( 250 volt or higher scale)
before testing your outlet for line voltage. You will also know not to apply voltage to a meter set up for ohms as
the current that will flow through the meter will promptly destroy it. There is a bit of a learning curve to operating
a Volt-Ohm-Meter but well worth one's time to become familiar. Also, if you work with high voltages, it is a good
idea to hook up the negative lead first and apply the test lead with one hand leaving the other hand in your back
pocket. An even safer way is to hook up both leads and then apply the voltage by switching on the unit you are testing.
No one needs to be a statistic.

The photo is of an older Simpson 260, my go-to Volt-Ohm-Meter. I have a digital meter as well
but it doesn't get used much.

Not sure whether anyone mentioned them yet, clamp meters are the way to go for AC current measurement. No disconnection required to insert a meter, can measure each leg separately, just clip the clamp around the relevant wire.
If you need to measure low currents and the meter isn't sensitive enough, loop the wire into a coil to multiply up (wire straight though is one turn, each extra time it goes through is one more) divide the meter reading by the number of turns to get the actual current.
I got a good enough from Evil Bay for less than a pie and a pint down t'pub, useful addition to the toolbox.

Dave H. (the other one)

I must have been born toooo early. I still use my VTVM. LOL

"Billy G"

We know what that is...Have one or two someplace...

Sent from my SAMSUNG-SGH-I337Z using Tapatalk

My Grandfather was a HAM operator (K1DGK). He built it from Heathkit. Now I have it.

"Billy G"