Understanding the Calibration Process for Sterilor Steredox Redox Sensor

Contact:
Do you deliver to the UK?

Agent:
Yes, we do.

Contact:
I want to by a redox sensor/probe for my sterilor stereos. Does the 110 euros cover the delivery cost to the UK and does the kit include the calibration fluid?

Agent:
No, unfortunately since Brexit we have extra fees for transportation. Calibration fluids are included. Which ones do you need?

Contact:
I mean Sterilor Steredox.

Agent:
Just a second.
https://ph-redox-pool.com/gb/sterilor/112-orp-probe-for-steredox.html

Contact:
Solution Etalon 470mv.

Agent:
https://ph-redox-pool.com/gb/pool-buffer-calibration-solution/2846-470mv-buffer-calibration-solution.html

Contact:
Thanks. I have ordered it.

Agent:
Thanks. Have a nice day.

Contact:
Hi Ollivier, I have received the electrode today and have gone through the calibration process with my steredox and the reading was 520mv not 470mv. Is this OK or is something wrong?

Agent:
It can be. Just put the in the calibration solution and then read the value.

Contact:
That's what I did.

Agent:
50 mv is not so much but just after it looks a little bit a lot. Let it run few days we will see. Contact me again.

Contact:
Do you mean let it run for a few days and then go through the calibration process to see if it goes down to 470 mv?

Agent:
Yes, we need to see if it is stable.

Contact:
Will do. Thanks.

Agent:
Redox is not a stable measurement, so 50 mv can be but usually we are +/- 30mv.

Contact:
Hi Olivier, The calibration today read 470mv. Hurray! Maybe the electrode didn't enjoy the travelling. Thanks.

Agent:
Excellent! The redox measure is very tricky!