Re: your mail

[Bernard L Cohen <blc+@pitt.edu>]

	I have made numerous measurements without difficulty,. You rotate 
the coil to find the maximum reading--- that takes care of the RMS 
question. The meters come with calibrations vs frequency, and the 
dependence on frequency is reasonably small over a large range. Nobody 
knows what frequency to worry about anyhow. Most worries are about 60 Hz 
and that is where they are calibrated. I think they are quite adequate 
except, perhaps, for research purposes

Bernard L. Cohen
Physics Dept.
University of Pittsburgh
Pittsburgh, PA 15260
Tel: (412)624-9245
Fax: (412)624-9163
e-mail: blc+@pitt.edu


On Wed, 1 May 1996 haes@MIT.EDU wrote:

> 
> Date: Wed, 1 May 96 11:49:50
> From: haes (Donald L. Haes, Jr. )
> 
> 
> Bernard Cohen wrote:
> 
> "There may be a confusion here between AC and DC magnetic fields. 
> I get the impression that your magnetic fields are DC, whereas the ones 
> that people worry about are AC. If you are worried about AC fields, a 
> meter to measure them costs only about $100, so it is cheaper to buy one 
> than to hire a consultant."
> 
> 
> Remember, you get what you pay for. If you buy a $100 meter, it will probably be single axis and 
> broadband. Thus, unless you really know what you are doing, it would be very difficult to make 
> true RMS measurements free of harmonics; unless you are one of those unscruplous-types that 
> stick a meter in a field, and actually believe everything you read without any thought. These 
> are my opinions; but please refer to ANSI/IEEE C95.3-1992.
> 
> Donald Haes
> MIT RPO
> haes@mit.edu
>