calibrated standard ph probe

[evad1]

i have a ac jr w/ standard ph probe. been running probally about 9 months now with out calibration, so i decided to calibrate the probe. before calibration ph was 8.5-8.6 and right when i did the calibration it dropped to 8.03. my question is how do i know that is accurate because the is a huge jump thanks dave...

and oh yeah how often should you calibrate your probe....

[Roy G. Biv]

After calibrating, stick the probe back into the 7 solution and it should read 7. Same with the 10. Also before calibrating stick it in the 7 solution to see how far its off before calibrating. I calibrate mine about every 3 months or when I see the readings out of the norm. I think the probe calls for monthly calibration though.

[evad1]

cool thanks..