CN0349 Drifting

Hi All,

I am using the CN0349 to measure conductivity in seawater.

However, the problem is that after calibrating, performing a sweep, calculating conductivity, the conductivity values tend to drift over time. It drifts over a matter of seconds.

I have made my own stain less steel probes to sit in a solution.

For example, my received conductivity values will start at 4.9 and every second decrease by 0.003. There seems to be no end in sight either, as it doesn't seem to settle.

I have 2 settling times

start frequency of 100khz

and I just repeat the frequency measurement five times

Excitation Voltage 2.0Vp-p, Internal PGA=1

The cell constant of the probe was calculated to be around 40

The measurement uses rfb = 100ohms

any help is appreciated.



added rfb, changed 100,000khz to 100khz
[edited by: jgirgis at 8:33 PM (GMT -4) on 3 Oct 2018]