Guest
|
 Posted:
Tue May 24, 2005 4:35 pm Post subject:
Need to measure 10 microvolt EMF noise |
|
|
Hello, I do eeg research (brainwaves). Signals are on the order of
10 microvolts (millionths of a volt). I need a battery powered
instrument to measure noise in my environment on the same order.
The Vellemans, Flukes, Teks, and so on I've looked at only get down to
..1 mV or 30 microvolts (Velleman 230). This won't do.
1 - does anybody know of a more sensitive, battery powered instrumcnt?
2 - could I build/buy some sort of battery powered amp or preamp for
the noise I pick up with an antenna?
(was thinking about a 9v guitar preamp)
Thanks in advance for any help....
Jim
|
|
Robert Baer
Guest
|
| Posted:
Wed May 25, 2005 8:35 am Post subject:
Re: Need to measure 10 microvolt EMF noise |
|
|
kroger@princeton.edu wrote:
| Quote: | Hello, I do eeg research (brainwaves). Signals are on the order of
10 microvolts (millionths of a volt). I need a battery powered
instrument to measure noise in my environment on the same order.
The Vellemans, Flukes, Teks, and so on I've looked at only get down to
.1 mV or 30 microvolts (Velleman 230). This won't do.
1 - does anybody know of a more sensitive, battery powered instrumcnt?
2 - could I build/buy some sort of battery powered amp or preamp for
the noise I pick up with an antenna?
(was thinking about a 9v guitar preamp)
Thanks in advance for any help....
Jim
Almost any operational amplifier will do the job. |
And you can add simple filtering: capacitive coupling to the
feed-forward resistor for the low end, and a shunt capacitor across the
feedback resistor for the high end.
I did that with a uA709 ages ago for a bio-feedback "machine" that
fit ina pocket and ran from a 9V battery. |
|
FAQ
Memberlist
Register
Profile
Log in to check your private messages
Log in