[TCML] Identifying an unknown current transformer

[David Speck]

List, 

I recently scored a set of unmarked Amprobe clamp-on current 
transformers.  I'd like to be able to calibrate and use them.  If I just 
measure their DC resistance, they come out to about 20 ohms each. 

I know that if current is passed through a CT without a burden resistor 
into a high impedance voltmeter, that very high voltages can be 
developed at even low source current levels.  I guess that I could start 
with an external burden resistor of, say, 1 ohm, and work upward, and 
see what kind of voltages I get for a known currents  through the 
detection loop. 

I just wondered if there was a more elegant way to determine 
electrically whether I have a plain  inductor, or a parallel inductor / 
resistor pair inside the "black box", and, if there is indeed a burden 
resistor present, what is its value. 

Thanks in advance,

Dave