Calibration of digital RS485 pH Sensor

Calibration of digital RS485 pH Sensor.

1) This pH sensor is with standard RS485 Modbus RTU

2)  regiester address is start from 0, Modscan 32 is from 1,so you need to add 1 on our original address.

3) The ID of digital pH sensor is 2.

4) register address 20 is to choose right calibration buffer. instruction code "0" is for pH4.0, 7.0 and 10.0 in foreign, Instruction code"1" is for pH4.01,6.86 and 9.18 in China. (the register address is 21 for modscan 32)

5) register address 13 is for calibration

5.1) firstly, you put the pH sensor in 6.86 or 7.0 , wait 1~2 minutes,then input code:1 and click"update",then the first calication point has been finished.

5.2) then you do second point calibration,just please note: please clean the sensor in pure water before put sensor in other calibration buffer. (the register address of calibration is 14 for Modscan 32)

6.after calibration of digital pH sensor, you see the value of register 15,the sensor is ok if slope value is over 90. (register address is 16 for modscan 32)