Wondering how often people calibrate digital ph meters or pens?
I've spent most of the weekend mucking around with calibrating the ista ph controller meter and it's been doing some odd stuff. Seemed to calibrate ok at calibration solutions of ph 7 and 4 and then tested ok but in tap water it was reading 6.5 when the digital pen was saying 7.5 (which is more sensible). I soaked the ista meter in a recharge solution and it seems more normal now or maybe reading .1 low.
The meter is about 9 mths old. I assume digital ph meters should last a few years?
This is the first time I've calibrated the ph meter and I probably calibrate the ph pen every 6 months.
I've spent most of the weekend mucking around with calibrating the ista ph controller meter and it's been doing some odd stuff. Seemed to calibrate ok at calibration solutions of ph 7 and 4 and then tested ok but in tap water it was reading 6.5 when the digital pen was saying 7.5 (which is more sensible). I soaked the ista meter in a recharge solution and it seems more normal now or maybe reading .1 low.
The meter is about 9 mths old. I assume digital ph meters should last a few years?
This is the first time I've calibrated the ph meter and I probably calibrate the ph pen every 6 months.
