seramic calibration: Can you use pH 4 instead of pH 9?
I read in a forum that you should start calibrating the pH electrode with pH 7 and, if you mainly use the unit in the acidic range (calcium reactor), use the pH 4 solution afterwards. Now your unit asks for pH 7 and 9 on the display. Can I use the pH 4 solution instead of pH 9,2 when pressing the "9" key? Will the calibration then be alright?
no, the unit must be calibrated with the pH 9.2 solution mentioned in the instruction. Calibrations with solutions other than the mentioned ones will either not be possible at all or lead to wrong measuring results!
Note as to avoid misunderstandings:
This question refers to an older unit (bright gray, rectangular shape with key buttons) that indeed needs to be calibrated with pH 7 and 9.2. As a general rule: All meters (including those which are part of a CO2 control unit) always must be calibrated as stated in the instructions included with the unit in question! The meter expects certain values during the calibration process, and providing it other values than the ones expected will lead to faulty calibration.
Dr. Bodo Schnell