different readings from ammeters same load

[mikilianis]

Hi I wonder if I am posting in the correct forum ,if by chance I am not then would some- one please be kind and direct me to the correct forum my query being as follows
I have 3 clip on current meters ( tong testers ) and when a load is measured I get different readings now all is very well if one just wants to check if a circuit is drawing a load , but when one has to explain the reason for the different readings ,
Meter A is a analogue meter
Meter B is a digital “ R.M.S. “ meter
Meter C is a digital meter
On an inductive load the readings are
A = 43 amps B = 42 amps C = 45 amps
On an resistive load the readings are
A = 95 amps B = 87.5 amps C = 103 amps
What could the reason be for the different readings.
The same load is used or tested by the ammeters
Thanks
Mike

 

[Guest123]

Hi.

Lots of things could affect the readings....different makes of tester, components, resistance of connections in leads and probe tips etc etc, tolerances.

 

[ian.settle1]

Hi.

Lots of things could affect the readings....different makes of tester, components, resistance of connections in leads and probe tips etc etc, tolerances.

And if they have been calibrated as well and when.

 

[sarge]

a and c are based on an average calculation on a sine wave, b however being rms i would say is more accurate as ist based on a dc equivalent.