Ph probe calabration

[Clivey]

Hi have tried to calibrate my ph probe and I am having a few issues, first time I calibrated every thing went well and has for some time. The last couple of days I've tried to calibrate and this is what I get every time,
First solution 7 I place the pin point probe and select enter it counts down and rises above 7 ph? It's reading 7.12 and the ADC reads 480' this is the Same with 9 ph solution the reading is 9.12 with a ADC 0268.
Can you tell me what this ADC means and how to correct this calibration issue, I also have this with my redox probe

Thanks redders

[Vinny]

How old is the pH probe?

[Clivey]

Hi the probes are about one year

[Vinny]

If the calibration steps were followed correctly, it could be an issue with the probe nearing the end of its useful life.

[Clivey]

Ok thank you, can you advise me if this probe is only one year old what's the best ph probe to buy that's totally compatible with the ghl profilux.

[GazzMan]

What does the probe read after you save the calibration and leave it in the 9 fluid for 10-15 to settle??