Re: 37XR inductance range

["Tesla list" <tesla@xxxxxxxxxx>]

Original poster: Finn Hammer <f-h@xxxx>

Mike,

You can trust the meter., however notice that the meter probably 
measures mH at 1kHz, and H at 50hZ.

Also note: From posts I made 28-12-05
Mike,

Pls. notice that few LCR meters can supply enough current to produce 
a usefull measurement on iron cored inductors. By exciting the 
windings with a typical LCR meter, the iron will be operating in the 
low "initial permeability" area of the B-H curve, and the readings 
will turn out to be too small.

Instead, you should connect the windings across a variac, with a 
Ammeter in series, and calculate inductance according to:
u = wLi

W = Omega = 2*pi*frequency = 2 * 3.14 * 60 = 377

Cheers, Finn Hammer

Yes, "u" is voltage across inductor being measured.
u = wLi

Rearrange for L you get:

L=u/wi
And can see that for a given current, voltage across 
inductorincreases with L and for the same voltage across inductor: 
current decreases with inductance. Which is what you`d expect.

Tesla list wrote:

> Original poster: "MIKE HARDY" <MHARDY@xxxxxxxxxx>
>
> 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?