PH calibration procedure
PH sensor is used to find the acidity or alkalinity of the solution it ranges from one to 14 and seven is the neutral point, less than seven is considered acid and below seven is alkaline. The PH sensor measures the number of hydrogen ions in the solution. Before starting the PH calibration, we should undergo some standard procedure, check here to determine.
PH calibration can be done in two ways.
Online calibration
Buffer calibration
Online calibration
In this method, we need a standard portable meter to measure the PH in the process line and if you find a minor difference compared to the transmitter value. You can adjust the slope to the current process value. If an error is greater than it is recommended to go for a buffer calibration.
Buffer calibration
1. Before starting the procedure make sure you have isolated the process line. Furthermore, make ready with the beakers, deionized water, and tissue papers needed for proper calibration.
2.Remove the sensor from the line and clean the sensor edge gently with the tissue paper. In addition, wash the sensor with deionized water to eliminate contamination of the buffer solutions.
3.A buffer solution for calibration is selected according to the process liquid if it’s an acid then 4 and 7 are used. And for the base 7 and 10 buffer solution.
4.The calibration menu in the controller will be the same for all manufacture you can easily spot the option in any makes. Select the buffer calibration, and it will intimate you to enter the value of the buffer solution you gonna use for calibration.
5.Next dip the sensor into a first buffer solution and wait until reading gets stabilized. After that clean the sensor throughout to avoid contamination.
6.Now dip the PH sensor into the second buffer solution until reading gets stabilized. After this step, the controller will automatically adjust the slope.
7.Now verify the PH calibration with other know solution and if the transmitter read an approximate value, then the calibration is successful. Else repeat the calibration step. Even output is not linear sensitivity of the sensor is lost need to replace the sensor.
