How to calibrate a Corelec Micro PH dosing pump without visible buttons?

Client: Hello

Technical Advisor: Hello

Client: I have a Corelec Micro PH brand dosing pump. I don't know if there is a possibility of calibrating the probe because there is no button on the body. So I assume that it needs to be replaced.

Client: Image of the dosing pump

Technical Advisor: Can you give me your email? I will look for the manual because there is a calibration process. If your device is old, there may be a screw to turn for calibration.

Client: Image of the dosing pump

Client: Image of the dosing pump

Technical Advisor: Is your probe connected to the Micro PH?

Client: Yes.

Technical Advisor: Okay.

Client: No numbers are displayed, only horizontal bars. Wouldn't it be easier to replace the pump with a newer one that is easily adjustable for calibration? I don't understand where the calibration buttons are on this model!

Client: email@email.com

Technical Advisor: I will look for it.

Client: Thank you. Please send the solution to my email: email@email.com.

Client: Thank you.