SEN0161-v2 inconsistent voltage readings

userHead Account cancelled 2020-06-22 05:24:27 1012 Views2 Replies
I'm using the SEN0161-v2 with a 3.3V power supply, calibration yielded values of about 1.5V for pH 7 and 2.1V for ph 4, which seem plausible to me.

However, in my target solution (pH 6-6.5, verified with a different pH meter), I'm getting voltages of around 1.8-1.9V, putting the measured pH around 5, way off.

The pH probe is then in a container with periodically rising and falling water level, so at times only the tip is submerged and at times the whole length of the probe. Could this be the problem? Is it intended that only the tip of the probe should be submerged and the full submersion causes wrong readings? Of course the BNC connector and signal conversion board are kept dry at all times.