- The technology uses resistivity discrimination between steam and water to provide indication
- Detection level is dependent on water purity and boiler operating conditions i.e. temperature and pressure of boiler
- Sensing element is a Probe with an insulated tip inserted in a side-arm Water Column. Voltage is applied to the tip: conduction occurs between the tip and the inside wall of the Column
- Resistance <0.1M Ohm indicates water i.e. Probe is immersed in water. Similarly, resistance >0.1M Ohm indicates steam i.e. Probe is in steam.
- An electronic discrimination circuit is used to discriminate the Probe resistance and generate the display logic accordingly
- A vertical display of multiple Green/Red LEDs provide resolution for the water level indication