Ammeters?

Status
Not open for further replies.
Joined
Apr 17, 2012
Messages
3,551
Location
West Michigan
Looking for recommendations on a basic clamp around (hall effect?) ammeter to use with auto diagnosis. Budget is a significant concern but I don't want to buy junk either. Looks like the internet is flood with units under $30 and over $100...
 
ESI makes decent low-current amp clamps.
Kind of have to think hard about this purchase though. Are you going to use it with an oscilloscope in the future?
I thought I'd never be using one with an oscilloscope, so I bought a stand-alone one. Now I'll probably be buying another. Would have been cheaper if I bought one that was scope-friendly.
 
Originally Posted by spackard
ESI makes decent low-current amp clamps.
Kind of have to think hard about this purchase though. Are you going to use it with an oscilloscope in the future?
I thought I'd never be using one with an oscilloscope, so I bought a stand-alone one. Now I'll probably be buying another. Would have been cheaper if I bought one that was scope-friendly.



Never considered this. Why would I use it with an oscilloscope?
 
One cool use of the ampmeter oscilloscope is to watch engine compression of a car that won't start by monitoring starter current. A cylinder that has no compression will have a dead spot in the current profile. Also you can sync up with the ignition to see if the engine is approximately in time.
 
Why do you need a hall effect (or clamp-on ammeter)? - I didn't realize they were really known for being super accurate for low-level amperage trouble-shooting.

Can you not simply use a mutli-meter in line with whatever circuit you're trying to measure current in?
 
Originally Posted by gathermewool
Why do you need a hall effect (or clamp-on ammeter)? - I didn't realize they were really known for being super accurate for low-level amperage trouble-shooting.

Can you not simply use a mutli-meter in line with whatever circuit you're trying to measure current in?


Yes that it an option but I would prefer to leave the battery connected while monitoring for key-off drain. Simpler and more repeatable.
 
Key off drains with anything but an expensive clamp meter is a waste of time...and even then accuracy will be suspect. Anything under 5 amps, even a cheap multi in line will be more accurate than a clamp. Clamps are too sensitive to how you hold them etc to be reliably repeatable in low amp draw measurements.
 
Originally Posted by PiperOne
Key off drains with anything but an expensive clamp meter is a waste of time...and even then accuracy will be suspect. Anything under 5 amps, even a cheap multi in line will be more accurate than a clamp. Clamps are too sensitive to how you hold them etc to be reliably repeatable in low amp draw measurements.

Most inexpensive to mid priced traditional DMMs have fairly high burden voltage in mA range, making them rather inaccurate, but at least they'd be consistent. You can use the A or 10A range to overcome this, alas, you will have less resolution that way.

From what I've seen with my Uni-T clamp meter, it does OK measuring mA current, as long as you remember to zero it out first.
 
Status
Not open for further replies.
Back
Top