Level capacitance electrode

An insulated electrode is placed in the boiler and the length should be sufficient to reach the water at all acceptable levels. The insulated electrode and the boiler work as a capacitor with the water and the steam as a variable dielectric medium. The capacitance of the ”capacitor” is converted into a current signal. 0% of water in the level glass corresponds to 4 mA and 100% corresponds to 20 mA.
The boiler level measuringresult is rather sensitive to foamin the boiler and deposits on the electrode influences negatively on the boiler level measuring results.

This boiler level capacitance electrode measuring method is relatively new as level control in steam boilers although it has been used for a long time for dry substances such as grains in warehouses.