Comparison and purchasing advice for Avady pH probes: delivery and calibration

Client: Hello
What is the difference between the following two probes
https://phcenter.eu/fr/avady/1313-sonde-ph-de-remplacement-pour-avady-réference-ayac08ac01.html

Technical Advisor: Hello

https://ph-redox-pool.com/gb/avady/3211-ph-probes-for-80-mm-avady--ayac08ac01.html

Technical Advisor: None, except for the price!

Client: Ok perfect
What is the delivery time if I order today?

Technical Advisor: 4 business days, Saturday at your place
via colissimo

Client: Ok perfect. Thank you for your help

Technical Advisor: You're welcome, feel free to contact us again! Have a great day

Client: Ok have a great day
Hello again

Technical Advisor: Hello again

Client: I had another question about this probe

Technical Advisor: Yes

Client: Do I need to calibrate it with pH7 and pH4?

Technical Advisor: Yes, the calibration depends on the probe and the controller

Client: Ok perfect, I should have some left that I bought last year

Technical Advisor: Yes, that's good

Client: Thank you

Technical Advisor: Have a great day

Client: Ok, have a great day
Hello again

Technical Advisor: Hello again

Client: I had another question about this probe

Technical Advisor: Yes

Client: Do I need to calibrate it with pH7 and pH4?

Technical Advisor: Yes, the calibration depends on the probe and the controller

Client: Ok perfect, I should have some left that I bought last year

Technical Advisor: Yes, that's good

Client: Thank you

Technical Advisor: Have a great day

Client: Ok, have a great day

Technical Advisor: Goodbye