pH value

• Effective automatic sensor cleaning
• Integrated lightning protection
• Galvanic separated serial communication RS 485 MODBUS
• WIFI
• Up to 12 measuring channels (pH and temperature) simultaneously
• Up to 8 output relays

Do you have a problem with cleaning the pH electrode during basification or neutralisation by means of lime milk? Do you have to clean the pH electrode all the time? Or do you have a system based on acid spraying and you are unhappy with the constant re-filling of the acid and with the fact that the electrode measures useless values after the spraying?

If you have the above-mentioned problems, why not try an automatic cleaning system built into the probes of the SPO 41MEK and SPR 41ME types?

Measuring of a pH value during water neutralisation by means of lime milk.

State of a sensor after a four-month operation without manual cleaning.

pH value is one of the most important electrochemical water parameters and one of the most frequent measurements. pH value significantly determines the behavior of chemical and microbiological systems. Therefore it is important for the functioning of biological wastewater treatment plants, fish breeding, food production and for monitoring surface and wastewater. In drinking water processing technologies pH significantly influences the course of chemical reactions and the corrosive properties of the water produced. Alcalinization and neutralization are among the most widespread processes.

Glass electrodes are used almost exclusively for pH measurement. Their quality significantly increases in particular mechanical resistance, stability and lifetime. These electrodes cannot be used for pH measurement in the presence of fluoride ions. In this case antimony electrodes have to be used.

One of the main problems of pH sensor implementation is the contamination of the main and reference electrodes, which lead to changes in their properties. Then intervention of personnel (in some cases even for a few hours) is necessary and in some cases it makes measurement impossible. This is the case with pH measurement during lime milk dosing, for example, if the lime milk and water reaction has not finished or with measurement of water containing aggressive iron. It is also very difficult to reach reliable, long-time and unattended operation for pH measurement in neutralization processes, and in chemically or biologically polluted surface waters.

The INSA Company has solved the above mentioned problems by implementing of mechanically cleaned sensors. This method has proved to be very efficient, undemanding and more convenient than other cleaning methods. This system, which has been tested through many implementations, also works at low temperatures and for chemically or biologically polluted waters. The system is very reliable, does not need any additional chemicals or water. It also works reliably for example with the dosing of lime milk or with the measurement of water containing aggressive iron.