# How to perform 200kHz-5MHz sweep while maintaining 200mArms?

Discussion in 'Electronic Basics' started by Michael, Sep 22, 2004.

1. ### MichaelGuest

I am performing a test to measure the impedance through electrode pads
placed on opposite parts of the human body. The protocol requires that
the measurement be made by maintaining an AC sine current of 200mArms,
sweeping the frequencies from 200kHz to 5MHz, and measuring the Vrms
between one electrode and a reference point on the body. The impedance
is to be calculated by dividing this voltage by the known 200mArms
current.

How do I sweep frequencies while maintaining a constant 200mArms
current using a HP 33120A (waveform generator w/ 0-15MHz freq and
0-10V peak to peak) or a HP 4192A (impedance analyzer w/ 0-15MHz freq
and -1V-+1V peak to peak)? Can I construct a circuit external to one
of these units and accomplish the 200mArms sweep? If not, what
lowest-cost set-up could?

2. ### Chris HolmesGuest

Hm, won't you need a high voltage to force that much current through the
body? I thought just a few mA could be lethal...

4. ### Tim AutonGuest

If you want to stop someone's heart it's much easier to stab or shoot
them.

Tim

5. ### Chris HolmesGuest

Maybe this circuit is for a cadaver lab. ;-)

6. ### Tim AutonGuest

In the Burke and Hare sense?

Tim

7. ### Robert MonsenGuest

Home electroshock therapy?

8. ### Glenn GundlachGuest

Yes, but the cleanup is much easier without the extra holes in the body.
gg

9. ### Fred BartoliGuest

It's better to try the setup on you first. At least you'll kill only one
person.

10. ### Fred BartoliGuest

Na, it should be 200 fA, but not 200 fucking Amperes...

11. ### JamieGuest

Hmm
last time i knew that much current passing through the body could cause
some fatel damage.
are you sure it isn't 200 Na ?