Using a multimeter.

Thread Starter

Trkcmc

Joined Feb 18, 2017
5
Hello, so not paying attention, I set my multimeter to amps DC, I connected my leads in series with the load to get an amp measurement. When I saw how high the meter reading was, I realized that I accidentally left the leads on the voltage connections of the meter. How was I still getting a reading on the meter? To be exact, I was testing amp draw on my truck battery. I was getting a reading of just over 5.4
 

Reloadron

Joined Jan 15, 2015
7,480
How was I still getting a reading on the meter?
Really would depend on how the meter is internally wired. All DMMs (Digital Multi Meters) are not the same including connections and switching. In the current mode the meter typically reads a voltage drop across an internal shunt, that being for most off the shelf common DMMs. To actually answer your question one would need to look at a schematic of your particular meter. That being my best guess anyway.

Ron
 

#12

Joined Nov 30, 2010
18,224
I set my multimeter to amps DC,
I connected my leads in series with the load
the leads on the voltage connections of the meter.
I was getting a reading of just over 5.4
Your meter measured 5.4 volts DC, but what that means is dependent on how the meter is built internally. (What Ron said)
My meter just ignores anything plugged into the voltage holes when the knob is turned to amps.
Yours does something else, but that something else is still worthless as a measurement.
 

Thread Starter

Trkcmc

Joined Feb 18, 2017
5
Really would depend on how the meter is internally wired. All DMMs (Digital Multi Meters) are not the same including connections and switching. In the current mode the meter typically reads a voltage drop across an internal shunt, that being for most off the shelf common DMMs. To actually answer your question one would need to look at a schematic of your particular meter. That being my best guess anyway.

Ron
Hmm, ok. This particular meter is one of my older Fluke meters. About 17 years old.
 

AlbertHall

Joined Jun 4, 2014
12,338
It was not entirely useless. At least the meter was not damaged (I assume).
Yes, it's better than leaving the meter on a current range and then connecting it directly across the battery. At best the meter will need a new fuse, at worst the magic smoke will be released. Been there, done that.
 

Thread Starter

Trkcmc

Joined Feb 18, 2017
5
Yes, it's better than leaving the meter on a current range and then connecting it directly across the battery. At best the meter will need a new fuse, at worst the magic smoke will be released. Been there, done that.
Honestly, I just finished replacing the fuse because I forgot to switch from amps to volts before testing battery voltage. Live and learn.
 
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