| | Maintaining a pH pen guide
My pen readings wouldn’t settle. It would jump +- 1.0pH. Changing out the battery fixed this problem. My pen takes Four LR44 Batteries (1.5v). Each battery voltages were 1.44volts. One battery cost $5. That didn’t sound right. I did a little research and found 303 batteries are exactly the same size & voltage. The cost for a pack of 3 were $7. I changed out the batteries except one to save money.
While I was at it, I recalibrated the pen. My pen came with buffering powder. I bought a bottle of distilled water while I bought the batteries. Follow the instructions. A kitchen measuring cup was exactly 250 ml needed for the calibration.