Hydrostatic pressure gauge sensor

Frequently in diesel tank applications you may install a 0m to 3m hydrostatic pressure gauge with a cable insulation rated for submersion in petroleum fuels.


The hydrostatic sensor is lowered to the bottom of the tank and measures the hydrostatic pressure of the fluid above the gauge. Hydrostatic gauges provide a measurement of the fluid height above the gauge. This measurement is directly converted into litres for the specific dimensions of the tank as set up in the HyDip device configuration online.

At the free end of the hydrostatic gauge cable you should find:

  • Two signal wires, one positive and one negative.
  • A ground wire made from the shielding on the cable.
  • A vent tube, which should be left unobstructed and exposed to atmospheric pressure. If this vent tube becomes blocked, or is subjected to fluid entry, the accuracy of the gauge measurement will be affected.

Take care to ensure that:

  • The breathable filter cap normally supplied by the gauge manufacturer is inserted at the end of the vent tube to protect it from dust ingress.
  • When shortening the cable length, use a sharp knife to cut the vent tube to ensure it does not get pinched or crushed.

Please refer to the sensor manufacturer’s documentation for detailed specifications and installation instructions.

Connecting to HyDip

  1. Identify the two signal wires, and connect them, taking care to get the correct polarity, to a green 2-pin terminal block connector plug using the screw fittings.
  2. If the cable supplied with the gauge is not long enough, install a weather proof junction box to connect the extra cable length. Cap the vent tube with its filter within the junction box. Normally there will be enough venting through the conduit glands to keep the vent tube at atmospheric pressure. Ensure all cable conduits are water tight to prevent external water entry into the junction box. If you are using a vented junction box make sure there is no possibility of water entry.
  3. Plug the 2-pin green terminal block into the socket on the HyDip Tank Gauging device (TK1 for sensor 1, TK2 for sensor 2 and so on). Note that:
  • The plugs will only fit the sockets one way up
  • The negative polarity of the gauge must be connected to TK1- on the HyDip side panel, and the positive polarity to TK1+. You should identify the correct wire polarity by referring to the wire colour coding specified in gauge manufacturer’s data sheet.


Pressure sensors have limits

Do not exceed the maximum pressure or depth rating for the pressure sensor as this may cause permanent damage to the gauge