Automotive DMM

[SuzukiGS750EZ]

Just bought a fluke 117 and realized it has everything I want, but noticed it was missing mA. How often do you use this in automotive? I usually just use for voltage and continuity or to verify specs, but can't remember using mA?

 

[Rabid Badger]

Just bought a fluke 117 and realized it has everything I want, but noticed it was missing mA. How often do you use this in automotive? I usually just use for voltage and continuity or to verify specs, but can't remember using mA?

mA range is useful for finding parasitic loads that drain your battery.

However, for that kind of thing I use a Uni-T UT210e clamp meter. Instead of having to break the circuit you can just clamp it over a conductor and read down to 1mA. You can pick one up for $30-45 depending on where you look and how long you're willing to wait. It's also a pretty well made meter; doesn't feel cheap at all. The next-cheapest clamp meter I know of that can do mA is $90.

 

[Bartleby]

Just bought a fluke 117 and realized it has everything I want, but noticed it was missing mA. How often do you use this in automotive? I usually just use for voltage and continuity or to verify specs, but can't remember using mA?

I never use it.

I use a low amp probe or a clamp meter for measuring currents.

 

[SuzukiGS750EZ]

mA range is useful for finding parasitic loads that drain your battery.



However, for that kind of thing I use a Uni-T UT210e clamp meter. Instead of having to break the circuit you can just clamp it over a conductor and read down to 1mA. You can pick one up for $30-45 depending on where you look and how long you're willing to wait. It's also a pretty well made meter; doesn't feel cheap at all. The next-cheapest clamp meter I know of that can do mA is $90.

I do parasitic draw tests across the fuses. Though I used to do it that way. Does the amp accuracy specs state that it would go down to ma to see parasitic draw...?

 

[Rabid Badger]

Does the amp accuracy specs state that it would go down to ma to see parasitic draw...?

That's what I said, isn't it?

 

[SuzukiGS750EZ]

.001 amp is 1 milliamp right? So the meter kinda does milliamp but not micro amp?

 

[JiminAZ]

Looks like from the table in post #4, resolution is 10 ma DC (.01A). I'd imagine that's fine for finding most parasitic draws.

I was poking around on Amazon, looks like the Uni-T UT210e meter is sold under a couple of different brands. Be careful found one exceptionally cheap lookalike but it didn't do DC current with the clamp meter (no Hall effect capability).

 

[Rabid Badger]

Yes. mA means milliamp. uA is the shorthand for microamp.

I've never heard of anyone using the microamp range for automotive work.

 

[SuzukiGS750EZ]

So this meter will be fine for automotive? I mostly use my meter for residential but also continuity, resistance and voltage. 10 milliamps is low enough for testing across the battery? I normally read across the fuses and use a chart to see the values.

 

[SuzukiGS750EZ]

The meter I have now I've never been happy with. Continuity buzzer is almost non existent. It shuts off randomly. I had it replaced once. The fluke meter my grandfather has, 88v, is a great meter and this one fit my bill. I saw all the specs and upon purchase I realized, no ma... lol

 

[MattT]

I do parasitic draw tests across the fuses. Though I used to do it that way. Does the amp accuracy specs state that it would go down to ma to see parasitic draw...?

It states 1mA resolution on the 6A range and 1% accuracy +/- 3 digits. With a 10mA current it'll read somewhere between 7 & 13mA in theory. I wouldn't trust it to actually meet that but it might be close enough for parasitic draw testing.

Also since you're volt dropping fuses check to see what mV accuracy the meter is capable of.

 

[2ndGearRubber]

I never use it.

I use a low amp probe or a clamp meter for measuring currents.

The meter I have now I've never been happy with. Continuity buzzer is almost non existent. It shuts off randomly. I had it replaced once. The fluke meter my grandfather has, 88v, is a great meter and this one fit my bill. I saw all the specs and upon purchase I realized, no ma... lol

Low amp probe and a lab scope is what you want for low amp situations. I've seen little value in the amp settings on meters. Unless you regularly have parasitic draws, you have no need for any amp readings on a meter. Look at the AESWave U-scope, that's what you want to look at amps.


I don't even bother with meters for draws either, amp probe on the scope, there you go.

 

[JiminAZ]

For the instrumentation guys in any industrial plant, most control loops run either 4-20 mA or 1-5 volts. For the mA stuff our guys use nice portable Fluke meters IIRC (in circuit not a donut)

But I digress. The meter under discussion does resolve 1 mA when set on the 6A range. My mistake I read the resolution when on the 10A range.

 

[SuzukiGS750EZ]

So... it'll be fine for my uses?

 

[Rabid Badger]

It states 1mA resolution on the 6A range and 1% accuracy +/- 3 digits. With a 10mA current it'll read somewhere between 7 & 13mA in theory. I wouldn't trust it to actually meet that but it might be close enough for parasitic draw testing.

Also since you're volt dropping fuses check to see what mV accuracy the meter is capable of.

That's the worst possible accuracy, they're usually better than that. Mine is dead-on with my 87V.

So... it'll be fine for my uses?

Yes.

 

[Fluelikesymptoms]

That's the worst possible accuracy, they're usually better than that. Mine is dead-on with my 87V.



Yes.

Rabid badger wont steer you wrong when it comes to dmm advice.


I think it is common to have the ut210e in alot of guys arsenal. However I wouldn't reach for this if it is your only dmm but you have the 117 so...

I believe there is an abundance of information on this meter. I don't think Uni-T is exactly considered a high quality, golden standard meter, but a good enough for the money meter. I think there are other meters made by them alot of people dont like but that model specifically is considered good.

There is also information on modifying the meter and improving it. You might not want to do this, but 35 dollars isn't a huge risk either.

 

[SuzukiGS750EZ]

Well that's good to know, at least it wasn't a waste of money! Lots of good info in here. I have checked sensor resistance and such, besides for the occasional parasitic draw test or resistance check that's about as sophisticated as I get on a vehicle.

 

[Vvmvbb]

So this meter will be fine for automotive? I mostly use my meter for residential but also continuity, resistance and voltage. 10 milliamps is low enough for testing across the battery? I normally read across the fuses and use a chart to see the values.

...just in case...I assume you mean in series with the battery not across it (across it will instantly blow the meter’s fuse).
And for each circuit, measure current across the circuits fuse socket with the fuse removed. What did you mean by ‘use a chart’?

 

[SuzukiGS750EZ]

...just in case...I assume you mean in series with the battery not across it (across it will instantly blow the meter’s fuse).

And for each circuit, measure current across the circuits fuse socket with the fuse removed. What did you mean by ‘use a chart’?

I have a voltage drop chart that converts mv to amp's. And yes, I know across the battery would blow a fuse lol. Ask me how I know!

 

[Vvmvbb]

Well that’s interesting. I never thought of measuring the voltage drop across a fuse’s resistance to determine current.

 

[SuzukiGS750EZ]

I found this article if you're interested. It was taught to me, easier on newer cars. I used it with success to find a bad circuit on an Audi a4 that the dealer said they "couldn't figure out"

https://us.autologic.com/news/testing-parasitic-draw-via-fuse-voltage-drop

 

[californiaHank]

So... it'll be fine for my uses?

Yes.

 

[SuzukiGS750EZ]

I love my fluke 179, got it at a great price. I messaged TPI to see if they could go over the unit as I was going to have it checked and then throw it in the "tools I can abuse" pile. I was told the first gen dmm like I have had a lower volume buzzer so they're going to replace that and update the firmware. We'll see. I'll probably reach for the fluke most of the time anyways, it's smaller and simpler.