I calibrate my Hanna HI 991001 meter with 7.01 buffer and then 4.01 buffer per the instructions. If I leave the probe in the 4.01 buffer after calibrating the pH will increase from 4.01 to 4.05 over the course of a couple of minutes, then stabilize at 4.05. If I rinse the probe after calibrating and put it in the 7.01 buffer I get a similar rise to 7.05 over a couple of minutes, then it stabilizes at 7.05.
Does this indicate a problem with the probe, the meter or the buffers, or not a problem at all? The accuracy of the meter is +/- .02 pH at 68 degrees. My readings are done at room temp of about 62 degrees.
Should I simply subtract .04 pH from all of my mash readings?
Does this indicate a problem with the probe, the meter or the buffers, or not a problem at all? The accuracy of the meter is +/- .02 pH at 68 degrees. My readings are done at room temp of about 62 degrees.
Should I simply subtract .04 pH from all of my mash readings?