Sensor [1]

An electronic device that can detect the presence of water, liquid product, product vapors or a loss of pressure or vacuum in the interstice [2] of a tank [3], a tank top sump [4], fuel dispenser [5] sump, or observation well.

Sensors are available that can only detect water, only petroleum products or can detect both water and petroleum products and differentiate between the two.

See also PEI/RP900 [6].