ferretman
Active Member
I have the red Hanna Checker ph meter. I keep the 7.0 buffer solution in the cap per the instructions. Now, every time I go to use my meter I have to calibrate it. The 7.0 range is always about .20 high and the 4/10 is constantly about .10 high(4.01 sol.) 6.59ph regestered at 7.62ph. The solution is always around 75F. Is this normal? Could it be a bad probe? I figured Hanna would be quality. The meter is used every 2-3 days. Any advise would be helpful.