clamp meter modification for mA uA?? can it be done?

Thread Starter

ninjaman

Joined May 18, 2013
309
hello,
i bought el'cheapo clamp meter from ebay, BSIDE acm81. i like the meter but i would like it more if it measured less than 1 mA. i work as an electrician and i would like to modifiy this meter if i can to measure less than 1mA. the usual thing would be to buy an earth leakage clamp meter. the clamp meter is to measure a live circuit that you can not disconnect. these meters measure to about 0.01mA. but they cost a lot of money and i probably wont use it all the time. multifunction meters that have that range are available but they are a lot more expensive. can i modify the signal coming from the transformer? i dont have to modify the display, as long as the meter shows a value in the amps range. i know that probably doesnt make sense but modifying the display would require programming. i was thinking a modification to the circuitry that changed the value of the signal before processing. thanks
all the best
simon
 

MaxHeadRoom

Joined Jul 18, 2013
18,995
Being electronic meter it could be tricky, the old moving coil you may have done it.
You might even be able to pick up one of the old versions cheap, as generally you can't give them away.
Good if only need it for AC.
What you need really is a resistance megger, you could get the dual versions, resitance at 500v/1kv etc, and low ground resistance down to .01ohm etc.
Max.
 

Thread Starter

ninjaman

Joined May 18, 2013
309
do you mean an insulation resistance meter? i have one, it gives 500v dc and measures ohms usually as high as possible. i was looking for a amp meter to measure around and below a milliamp, usually down to 0.01mA. most earth leakage meters have a 200mA setting on their meters.
 

Yaakov

Joined Jan 27, 2019
1,532
do you mean an insulation resistance meter? i have one, it gives 500v dc and measures ohms usually as high as possible. i was looking for a amp meter to measure around and below a milliamp, usually down to 0.01mA. most earth leakage meters have a 200mA setting on their meters.
What are you actually measuring? If you loop the wire around the clamp, it will act as the primary of a transformer and instead of one turn it will be N turn with the associated ratio.

I have one of these, and it works very well for it's intended purpose, note the 10x slot...

https://www.amazon.com/gp/product/B0000YHN9W/
 
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