How To Use A Multimeter To Test

Talking about
Digital and analog meters...
I'll take a good analog meters any day over any digital one.
I think it's dangerous to check for bad fuses with a digital one. They lie...


 
KBeitz said:
Talking about
Digital and analog meters...
I'll take a good analog meters any day over any digital one.
I think it's dangerous to check for bad fuses with a digital one. They lie...


Click to expand...
????
Both have their advantages.

Simpson 260 is the gold standard for analog and have several but last used one long ago.

HF digital are not worth the cost (often free) but are great when rough duty combined with minimal accuracy needed (enteral voltage or general resistance)

For exact the Fluke comes out.

Checking fuses is a simple operation performed many ways via ohm or volts measurements and this depends on need of the troubleshooting but cannot remember a meter not indicating correct status of a fuse.

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hman said:
Any multimeter that can find AC and CD voltages and resistances can be used to diagnose a motor. I do own a good Tektronics meter, but use a Harbor Freight giveaway for most of what I do
Click to expand...
Well, I don't know about that. I have several meters, including a Fluke 88, and another of similar pedigree. They used to stay in the toolbox for "special occaisions" and my $6 meter was used for ordinary duty. I was using the cheapy, diagnosing a starting/charging issue with a car. The meter told me the battery had 10.2 volts, yet it started the car just fine:cautious:. And now, with the car running, we see a voltage of 12.2:confused 3:. Turn the headlights and heater fan on (large electrical loads), and the voltage stays above 12.0. At this point, I smell a rat. Break out the good meter, and see 14.6. At THIS point, I send the cheap meter to where it belonged all along (the garbage can). I will not buy another one. A similar issue concerning resistance, chasing sensor issues or the like, could really complicate my life. I need NO help along those lines.;)
 
Yup...

We were doing site pm work where the cell sites had 48 volt battery plants and we were using one of the many hf digital meters and observed lots of swelled up batteries and noticed the voltages were high by just a bit which would cause the damage.

Our responsibility at that time was not battery plant so we did not carry the Fluke.

The responsible party came by and the voltage was correct...but it seems that brand of battery just self destructed.

Later confirmed the hf unit in DC was off by 4% in dc.

Others indicated pp voltage in ac instead of rms so you got 150 or so on 120 vac circuits...

They almost are worth the price...

The hf ones are good for TROUBLESHOOTING where an indication of presence of voltage is all that is needed.

If performing alignment or adjustment where things matter then Fluke or other known good unit and insuring it is correct.

Bottom line is just like anything else...Use proper tool for the job and use it correctly.

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westerner said:
hman said:
Any multimeter that can find AC and CD voltages and resistances can be used to diagnose a motor. I do own a good Tektronics meter, but use a Harbor Freight giveaway for most of what I do
Click to expand...
Well, I don't know about that. I have several meters, including a Fluke 88, and another of similar pedigree. They used to stay in the toolbox for "special occaisions" and my $6 meter was used for ordinary duty. I was using the cheapy, diagnosing a starting/charging issue with a car. The meter told me the battery had 10.2 volts, yet it started the car just fine:cautious:. And now, with the car running, we see a voltage of 12.2:confused 3:. Turn the headlights and heater fan on (large electrical loads), and the voltage stays above 12.0. At this point, I smell a rat. Break out the good meter, and see 14.6. At THIS point, I send the cheap meter to where it belonged all along (the garbage can). I will not buy another one. A similar issue concerning resistance, chasing sensor issues or the like, could really complicate my life. I need NO help along those lines.;)
Click to expand...
The cheap meter indicated "voltage present" ...where it matters the accuracy of the tool matters...The hf units usually not accurate.

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The cheap meters have their place for "is it there or isn't it" type of tests where absolute accuracy is not required.
I use a Radio Shack medium quality one mostly
 
Because I actually work for a power company & have commissioned a power generation plant to the point of actually putting it online, I'd like to add just a few notes. OL, as someone that used to work there thought: Does NOT mean it is OK to test 7200V Phase to Ground with a Fluke 87. I think the meter has a limit of 1000V. OL (overload) should be left to Ohms. OL when trying to read Amps, well, it's time to buy another fuse. What you think should read OL when measuring Volts can kill you. When in process of building said power plant, all the contract electricians kept trying to measure DC + to Gnd. Um, it doesn't work that way. They didn't want to find DC - & many couldn't even read the schematics to locate a suitable DC - near the point they wished to check anyway. Know what you have. Know how to measure it. Know how to understand your results before venturing beyond a wall receptacle.
 
If you want to measure Volts/Amps/Ohms use a digital meter.
If you want to test a circuit, use a good quality, sentitive analogue meter.
Some knowledge is necessary, without it, your tests may be dangerous to you and others and measurements will be meaningless.
BROCKWOOD makes the point!
 
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