Re: 37XR inductance range

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Steve Ward <steve.ward@xxxxxxxxx>

Does anyone know if LCR meters are also incompetent for measuring
ferrite based inductors?  This could be very bad since the large power
supply ive been developing strongly depends on my LCR meter
measurements.

Anyone know of a good high power home-brew L-meter?

Steve Ward

On 1/6/06, Tesla list <tesla@xxxxxxxxxx> wrote:
> Original poster: Terry Fritz <vardin@xxxxxxxxxxxxxxxxxxxxxxx>
>
> Hi Mike,
>
> What are you measuring?  In general, any LCR type meter us useless on
> iron cored inductors or inductors that have a core with a significant
> hysteresis.  Since you inductance is relatively high, I assume your
> inductor is cored.
>
> The core needs a certain minimal amount of energizing current to
> reach its normal magnetization curves.  Typical meters use very small
> currents that can't energize the iron and such properly.  The meter
> uses different current levels for different ranges so the readings
> vary, but the readings are probably far off anyway.
>
> Probably best to run 60Hz AC voltage across it with a variac and
> measure the current.  Then you get   L = V / (I x 2 x pi x 60).
>
> If you graph the inductance vs current, it starts out very low,
> reaches a long flat area and then drops again as the core saturates.
>
> Cheers,
>
>          Terry
>
>
> At 11:51 PM 1/5/2006, you wrote:
> >I recently purchased the Meterman 37XR per the list members
> >favorable use. I was just measuring the inductance of my variable
> >ballast, and a few hig power isolation xfmr I have laying around.
> >One measured 365 mh. When I changed ranges to henrys, it
> >dramatically changed to 0.260H ! Does anyone else notice this vast
> >discrepincy? Can I trust the meter?
>
>
>