. If you have any questions, please let us know.

Good morning

I have 2 calibration points 7 and 4, by performing the operation point 7 was ok and point 4 error after 2 tries obviously changing the product of solution 4 and cutting it would feed it each time I I repeated the calibration operation 4 . So I rinsed the probe and put it back in its place. I restarted and the value returned to 7.2 after about 10 minutes.

My question is: what is solution 4 for? And is my probe accurate now or do I have to repeat the operation until the calibration of solution 4 is ok?

Thank you for your answers !

Good morning

Do this little test instead, we will know if your probe is still working

https://ph-redox-pool.com/gb/content/16-ma-sonde-ph-est-elle-hors-service-