(Click image for a larger view)
The ELECTRONIC SENDING UNIT for FUEL, OIL, and POTABLE WATER tanks provides a continuous readout of the liquid level in your tank. The unit (which has no moving parts) consists of a sensor probe and an amplifier. The amplifier components, which are located in the mounting plate assembly, are encapsulated in an epoxy resin compound to seal out moisture and other contaminants which could affect the operation. The mounting plate assembly has the same 5 hole SAE bolt pattern mounting dimensions as the standard float sending units they replace. The meter (receiving unit) can be remotely located close by or in your dash.
FUEL SENSOR PROBE (Gasoline or Diesel)
The probe is constructed of concentric tubing (a small brass or alum. tube inside a larger aluminum tube). The tubes, which are separated by small insulators to keep the tubes from touching, acts as a capacitor that has one value in air (empty tank) and changes in value as the fuel level rises inside the probe. The amplifier converts these values to a signal suitable to drive a standard meter or other display device.
WATER SENSOR PROBE
The probe consists of a PVC tube with a bare stainless steel (ground) wire running along the outside and an insulated (sensor) wire through its center. The PVC tube is to hold the wires in place. The output to the meter changes as the water level rises on the sensor wire.
The probes come in 12 inch increments and can be cut to any length down to the next lower increment. We prefer to build them your required size, however, for which there is no extra charge. It saves you from having to shorten and recalibrate the sender.
UNAFFECTED BY CORROSION
Even if the sensor did corrode (which is improbable because of the high quality materials used), a thin layer of corrosion on the surface of the sensing elements would not change the accuracy because the gap over which the capacitor works is almost 1/10 of an inch whereas corrosion would be measured in 1/100ís.