Peter Bennett wrote:
On Thu, 10 Jan 2008 18:48:00 GMT, ehsjr
wrote:



The whole thing, at this stage, has to be outdoors - and that
includes the test equipment. The inductance measurement changes
with temperature, AIRC, but I don't know yet how much of that,
if any, is test equipment error. Using the frequency change
approach vs delta L makes a wider input, and small changes
in level were easier to see. I hadn't thought of pulsing a
current and measuring V.

I may have to jury rig something for testing to bring the
equipment inside where the temperature remains the same.

Ed


As a test, could you not bring everything into the kitchen? Measure
the inductance at room temperature, then put the coil in the fridge,
and watch for inductance changes as it cools.




I don't think my wife would allow me the privilege
of living if I stuffed a 46" long PVC tube in
the fridge. :-)

Ed