Im learning a lot about ph meters. Calibrating at the 8.5-9.0 for the high point is whats doing it. That can skew an actual reading by a lot depending on what the solution your testing is suppose to be. So for me trying to get to 6.5 from what Im understanding being more than 1.0 off during calibration, can cause that reading to be off by 1.5ph so Im thinking because I set the high point reading at 8.8 the last time I did it, all my solutions are off by at least 1.8-2.0 more basic than they should be.....no more high point calibration for me.
Or at least this is what googles ai gathered for information. I asked if the low and neutral were calibrated right but the high point was off by 1.5 how much would it affect readings and thats the gist of the answer it gave me. It also says the more acidic the solution the more it would be off because ph meters measure on a curve with specific set points and one being off affects the entire curve