Dual-Point Hydrostatic Sensor

The Dual-Point Hydrostatic Reservoir Sensor accurately detects fluid level change in the reservoir and interstice of a double wall storage tank. The Dual-Point Hydrostatic Reservoir Sensor is ideal for high groundwater areas, and can differentiate between a high level alarm condition and a low level alarm condition. If an inner-wall leak occurs, the brine seeps into the tank triggering a low-level alarm, if an outer wall leak occurs, fluid seeps into the interstice triggering a high-level alarm.

Key Features

  • Meets California’s requirement for secondary space monitoring for tanks as required by AB 2481

  • Withstands removal from reservoir several times a year without sensor damage

  • Clear plastic housing for visual inspection or float operations 

  • Rests in salt brine solution of up to 30% calcium chloride

Product Form

Part Number




Dual-Point Hydrostatic Reservoir Sensor

Vented riser cap assembly included



Fuel Compatibility

Gas, Diesel, Kerosene, Jet Fuel, Aviation Gas, E15, E85, Bio-Diesel 20, Green Diesel, Waste Oil, Motor Oil

Reservoir Solution Compatibility

Up to 50% ethylene glycol in water; up to 50% propylene glycol in water; salt brine solution of up to 30% CaCl

Alarm Notification

Normal: Float is in the Center position (correct amount of brine in reservoir)

Low Liquid: Brine drops below 1.2” (3cm)

High Liquid: Brine Rises above 13.13” (33.4cm)

Sensor Out: Sensor not communicating to ATG Console

Operating Principle

Reed Switch / Float

Product Activation Height

Low Liquid 1.2” (3cm), High Liquid 13.13” (33.4cm)

Operating Temp

-13 to +122°F (-25 to +50°C)


17.3” (43.9cm) High, 2.5” (6.4cm) in Diameter

Standard Cable

12ft (3.65m)