pH Sensor

The operation of the pH sensor is based on a zirconia membrane and an Ni/NiO or Cu/Cu2O electrode that measures the oxygen partial pressure of the testing solution. The pH is calculated using the Ag/AgCl reference electrode signal and temperature as additional input signals. The pH sensor can also be used as a reference electrode in an environment with a known pH. The operating temperature of the pH sensor is from about 180 °C to 360 °C, but the maximum operating temperature of the Ag/AgCl reference electrode limits the pH measurement to a temperature of 300 °C.