Mine did that not 15 min ago when I calibrated mine. I pulled the probe out cleaned it, shook the solution and put it back in. It got down to 7.24. Called it good. repeated the steps with the 10.0 solution. stuck probe in tank and it read 7.82. Added some 8.2 Ph buffer and the display is reading 8.17.
Tony
I cleaned it before this calibration also, maybe I will go back and give it a better cleaning...
My Ph after close to an Hr of adding the 8.2 Ph buffer
Tony
:hmm4: Your tank is kind of warm... no?
Its actually where I like it. I used to keep it at 79° . At 84° every thing is groovy
Don't read too much into the displayed value during the calibration. The value shown is really just a number related to the millivolts sensed on the port at each calibration point. It is only after the software applies a mathematical conversion that it displays the pH.
Best thing to do is follow the procedure then do a dip in your 7.0 and 10.0 solutions to check your final results.
Did your readings show very close to 7.0 and 10.0 when dipped in the cal solution after the procedure?
Just a thought but when I first connected my probe I had it on the wrong port. plugged it into the Ph port instead of the Ph/Orp port and butter baby.
Tony