S3 Senders suitable for Water, Grey Water, Diesel, and Petrol.

European output is the most common in the UK and the rest of Europe and is stocked by Tek Tanks up to 600mm in length.

High Resolution is only available in lengths up to and including 400mm.

Please Note: Senders over 600mm long, High Resolution and American output are subject to a maximum lead time of 10 working days. The lead time normally however  is 2-3 working days.





  • 316 stainless steel
  • 1 ¼” BSP thread
  • 0-190 ohms (European) or 240-30 ohms (American)
  • IP67
  • Simple to install and remove
  • Very reliable
  • Lengths from 150mm – 1600mm +

Robustly made from 316 stainless steel and fitted as original equipment for over 30 years by most of the major British and European boat builders. These senders work on the simple principle of twin magnets in the float tripping a series of reed switches securely housed, and doubly insulated inside the stainless tube.

Over the years senders have been improved with advances in reed switch technology, allowing more switches to be fitted inside the senders, giving the better resolution required by modern digital displays.

We now offer high-resolution senders from 150mm to 400mm.  These senders are the same as the standard resolution in every way except we have placed the switches every 10mm instead of every 20mm giving you more accuracy in the shallowest of tanks.

They have proved very reliable and this technology is used by all major European truck and bus manufacturers and on many off road vehicles.

Longer senders and bespoke options are also available including different outputs; 0-5v, 0-10v, 4-20ma. Please call for more information.

There are two standard resistances, 0-190 ohm, used mainly in European gauges and 240-30 ohm used by American gauge manufacturers. Senders and gauges must have the same resistance range.


Simply connect one wire to earth and the other wire to the sensor cable on the gauge.


Use these torque settings when screwing the S3 sender (with o’rings mounted) into a flange:

Steel Flange:  9 ± 1 Nm
Nylon Flange:  7 ± 1 Nm


The European specification IPFR Fuel Gauge and the IPWR Water Gauge are both suitable for the European Standard and High Resolution senders.

How to fit an S3 Sender Video

Additional information

Length (mm)

150, 175, 200, 225, 250, 275, 300, 325, 350, 400, 450, 500, 550, 600, 650, 700, 750, 800, 850, 900, 950, 1000, 1100, 1200, 1300, 1400, 1500, 1600

Output Type

European (0-190 ohms), American (240-30 ohms)


Standard Resolution, High Resolution

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