I installed a new ultramat 62 weeks ago. We have been checking zero and span daily. We find the zero has drifted by 1%-2% every day. We are measing 0-10PPM CO2 in air in an air seperation plant.
The span seems to be repeating within spec but the zero has this weird drifting. We are using a CO2scrubber to scrub the air we using for our zero gas. Has anyone experienced this issue?