Ph probe calabration

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

How old is the pH probe?

Hi the probes are about one year

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

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.

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

If you're in the USA, genuine GHL probes can be purchased on our US online store, www.ghlusa.com

I don't know as I've not tried that yet, what should happen ?

Leaving it in there for that amount of time will allow the probe to stabilize the readouts and tell you if the probe is still giving you false readings or not.

So am I right in thinking if I calibrate and then save the result do I just leave the probe in the ph 9 solution for 10/15 min and should It return to 9 if it's been saved a 9.12. If it stays at the reading of what it's been saved at does this mean a faulty probe?

How old is the calibration fluid? It is also possible that the fluid became contaminated and changed the actual pH value of the fluid.

If this is not the case, then the probe could be due for replacement if the reading is still 9.12 after sitting in the 9 pH solution.

Hi the calibration fluid is new, it would not be contaminated as I have been very careful in testing the ph

Quote:

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Originally Posted by Clivey

So am I right in thinking if I calibrate and then save the result do I just leave the probe in the ph 9 solution for 10/15 min and should It return to 9 if it's been saved a 9.12. If it stays at the reading of what it's been saved at does this mean a faulty probe?

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No, I would do it again, have you fully cleaned the probe, I soak mine in white vinegar for an hour and clean with a soft tooth brush, then fully rinse off in tank water, then dry it off before I calibrate, I do this every 3 weeks.

Hi Gazzaman thanks I will try this tomorrow and let you all know results

Hi have re calibrated and it was a lot better the reading was 705 and 902

What did it read in the solution

When placed in the solution 7 it calibrated at 705ph and for the 9 it was 902 ph

7.05 and 9.02. Awsome mate

Thanks