S5U Tank Level Sensor, 1-1/2NPT - 17"

Wema's most versatile tank level senders are the SSS/SSL, S3U, and S5U models. These single stainless steel senders typically have an NBR (Nitrile Butadiene Rubber) float, and differ only in their mounting methods.
SSS/SSL has a basic SAE 5-hole pattern, and typically mounts with gasket and screws; S3U has a 1.25" BSP threaded mount; S5U has a 1.5" NPT threaded mount.
These single stainless steel models can be used in water, gasoline, hydraulic oil, or diesel.

The S5U sensor has a float which rises and falls on the central shaft with the level of liquid in the tank.
The sensors are fully insulated to protect against dangerous electric currents inside the tanks.
This is an extremely important safety feature, because it protects against electrolytic corrosion, as well as the danger of an explosion when used with gasoline.

The mounting thread is 1-1/2" NPT, tapered male National Pipe Thread.
Retro-fit/replacement installations will generally use the existing mounting hardware.

For new installations, a user supplied 1-1/2" female NPT fitting will need to be mounted on the tank.

The sending unit length is measured from the top of the threads to the tip of the gauge.
It should be at least 1" less than the depth of a plastic tank, and 3/4" less than the depth of a metal tank.
Note: if the top of your metal tank flexes, deduct one (1) inch from the depth (like a plastic tank).

• For use with diesel, gasoline or water
• Availble in 1" increments from 4" to 60"
• Can be used with any Wema System dash gauge
• Sensor electrical reisitance range is 240 (empty tank) through 33 (full tank) Ohms (Standard Aftermarket)
• All 316 stainless steel
• Very easy to install
• Long term reliability under severe conditions
• Fisheries stocks most incremental lengths (inches); odd lengths can be special ordered &&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&&& Wema's most versatile senders are the SSS/SSL, S3U/S3, and S5U/S5 models. These single stainless steel senders typically have an NBR (Nitrile Butadiene Rubber) float, and differ only in their mounting methods.
• SSS/SSL senders have a basic SAE 5-hole pattern, and typically mount with a gasket and screws
• S3U/S3 senders have a 1.25" BSP threaded mount, and come in models for American (S3U) and Euro (S3) dashboard gauges
• S5U/S5 senders have a 1.5" NPT threaded mount, and come in models for American (S5U) and Euro (S5) dashboard gauges
These single stainless steel models can be used with water, gasoline, hydraulic oil, or diesel.

The 1-1/4" BSP threaded, S3U Liquid Level Senders in this entry have an internal resistance of 30 ohms when the tank is full, and are only suitable for use with matching 30 ohm "American" dashboard gauges.

The 1-1/4" BSP threaded, S3U Liquid Level Senders in this entry come with American Standard Outputᵠ (33 ohms at full) but have a BSP threaded mount so they can be used with European manufactured tanks.
They are only suitable for use with matching 30 ohm "American" style dashboard gauges. Their length is measured in inches.

The S3U sensor has a float which rises and falls on the central shaft along with the level of liquid in the tank.
The sensor unit is fully insulated to protect against dangerous electric currents inside the tanks.
This is an extremely important safety feature, because it protects against electrolytic corrosion, as well as the danger of an explosion when used with gasoline.

The S3U sensor has 1.25" BSP - straight male British pipe - threads that seal with an O-ring.
Use this sensor with a threaded Top Adapter (FL-2WE) (see Related Products, below) which will bolt to either a standard American SAE 5-hole mount (2.125" bolt circle), or the larger European 5-hole mount pattern, on your tank.

The sending unit length is measured from the top of the threads to the tip of the gauge.
It should be at least 1" less than the depth of a plastic tank, and 3/4" less than the depth of a metal tank.*
If the top of your metal tank flexes, deduct one (1) inch from the depth (like a plastic tank).

• For use with diesel, gasoline or water
• Available in Imperial measurements in 1" increments from 4" to 60". (Metric lengths available from 500mm to 1050mm – see S3 BSP Threaded Senders.)
• Sensor electrical resisitance range is 240 Ohms (empty tank) through 33 Ohms (full tank) (Standard Aftermarket)
• Can be used with any Wema System Dash Gauge with the same resistance (Ohm rating)
• Simple, reliable and accurate reed-switch/magnetic field design. The float is the only moving part, minimizing potential mechanical failures
• All 316 stainless steel
• Includes 38mm and 43mm O-rings for sealing
• Operating Voltage: 12/24V DC
• NBR mounting gasket (1Pc) and screw (5Pcs) included
• Custom lengths can be special ordered

American Standard Outputᵠ
Standard American gauges and senders are designed to work with a variable resistance from 240 ohms empty to 33 ohms full, while European products are designed to work with a variable resistance from 0 ohms empty to 180 ohms full.
Senders and the dashboard gauges they are paired with must have the same resistance range.
The American Standard Output is non-linear and is based on American Boat and Yacht Council standards with plus or minus 5% tolerance for range difference.
Resistance readings at different levels are as follows:
• 33 ohms at 100% 
• 67.5 ohms at 75%
• 105 ohms at 50% 
• 142.5 ohms at 25% 
• 240 ohms at 0%


* Note – Fastener torque setting for mounting (with O-rings) to metal tanks is 9 +/- 1 Nm; plastic tanks is 7 +/- 1Nm