pH probe calibration


New member
I just bought a PM1 and a lab grade pH probe and am wondering if I calibrated it correctly. I do not have a display for the apex and the instructions in the manual say there is no web interface for calibration. But I found online where if the Apex firmware is 4.1 or higher it is possible to calibrate. Here is what I did:
Via web went to configuration then probe set up. I put the probe in the packet of 7 solution and clicked calibrate. The numbers fluctuated a little but quickly settled in. I rinsed the probe, shook it off and put it in the 10 solution. It took a little while but settled within a minute or two. I clicked finish. Was there anything else I was to do? The probe is reading and it is fluctuating throughout the day but it is reading at 7.8 which is low compared to the titrated test.
Has anyone calibrated a probe without the display and if so, how did you do it?


New member
I did mine from the webpage
I am running 4.20L_CA12
Configuration, probe setup.
then change the drop down to PH
then click calibrate.


New member
Thanks! I did that but I don't think I clicked update so maybe that's what the problem is...I hope. Otherwise my pH is way off:( I'm waiting on more calibration fluid and will recalibrate.


Dad with Triplets!
After u hit finish I believe you have to hit update at the bottom of the page to send the info to the apex.