First of all I'll editorialize by saying this is a paranoid fear unless she
frequently travels to areas of very high RF field intensity. Secondly, a
'wearable' instrument will be a compromise, at best. A real spectrum
analyzer with a calibrated antenna is what you need for 'accurate'
frequency-dependent measurements.
End of editorial.

The simplest way I can think of to do this job is to use the Analog Devices
8307 log detector IC. This chip has an accurate 90 dB measurement range that
goes down into the microvolt region and operates to over 1Ghz. If you built
a series of these detectors, each one with a broad bandpass filter front-end
for the appropriate frequency range, then you could measure all the log
output DC voltages with a PIC processor and light up LED indicators when a
threshold limit is exceeded. As an embellishment, you might arrange a set
of, say, 6 bar-graph LED modules oriented in a vertical position
side-by-side with each other. This would provide a crude spectrum analyzer
display.


Joe
W3JDR


"Ed Bailen" wrote in message
...
My wife recently had a defibrillator implanted. The folks that
manufactured it kindly sent her an email discussing the varoius bands
and field strengths it had been tested against E field and H field).
She is concerned about exposure to RF both from our mobile VHF and HF
operations, and from the un-shielded multi-gigahertz processors in her
lab. We would like to come up with an absolute (not relative) field
strength meter that we can use to evaluate field strengths (mainly E
field) at various frequencies. I could not find anything on Google.

I can cobble something together wirh an antenna, a tuned front end, a
detector, and a peak sampler, but how to calibrate it?

Any suggestions?

TNX Ed Bailen - N5KZW