The more I think about it the more it seems like storing it in 4 could be causing the problem. I suppose it could be a coincidence, but it will calibrate at 4 but not 7. Hmmmm, interesting. Send a quick email. Who knows, you might get a response tomorrow.
Opie Yutts Reviewed by Opie Yutts on . Rhizome/Opie/Anyone who uses Truncheon PH Meter Help!!! I can't get mine to calibrate lately! I've tried cleaning the probe, and even changing the contact ring (only had it about a month....:() but I keep getting that flashing green 5. It calibrates to the 4.0 solution I have (made by BlueLab) but not the 7 (made by Hanna) although it DID calibrate to the hanna solution previousyly. Any tips? I use new solution each time and check it once a week, keep the cap with 4.0 solution damp on the sponge and rinse the probe each time I use it. HELP!! Rating: 5