Hi.
I need some help with my application.
The principal idea is in a future measure a magnetic field using a magnet-resistor circuit (internaly: use a bridge weastone).
(see the diagram please...:smileyhappy:)
- ok before to do this idea, i need to measure on mico-volts o nano volts (if exist some posibility) with this card
- i need a reference voltaje of 2.5v. i suppose to use a voltaje divisor with resistors of 1K.(Letter R)
- before to use the circuit i'm using another voltaje divisor with resistors of 1K. (Letter S)
- Using a very-good cable (twisted-pair, low-impedance, shielded) aprox 6 ft of long. i send both signals to compare.
- actualy i used both metods Diferencial (Ai0-Ai8) or NRSE(Ai0-AiSense). to compare the best metod.
- i using resistors to Ground-Reference, (in accordance with M Series User Manual page 4-12) to reduce the noise
- i'm using the channel 1 to check the maximum measure that i can hope
- i'm program Ao0 with 5V
- my range to measure is 0.1v to -0.1v
my results are:
using standard deviation.
on Ai0 - 2.0e-5 v
on Ai1 - 1.04e-5 v
ok after this story,
-i need to reduce the noise
-have a better measure
some idea?
why i can't use 16 bit of resolution as minimum?. to have 3e-6 V
which is the better technique to measure microvolts
thanks so much if you can help me!!
i have a headache with this problem, hahaha.....