Wema USA, Inc

About US

Overview

Over twenty years ago, Wema started designing and manufacturing fuel and water level senders for the leisure boats industry. Since then, we have gained a global reputation as the leading manufacturer and provider of senders and sending solutions. Sender production in 2011 has surpassed 2 million units. In addition to liquid level senders, Wema has expanded its product range to include temperature sensors, pressure sensors, and full line-up of gauge instrumentations such as level gauges, voltmeter, tachometers, GPS Speedometers, etc.
Applications
Today, our market orientation is 5 fold: agricultural, automotive, construction, marine, and power equipment. To ensure a long product life in demanding environments, Wema uses stainless steel and non-corrosive materials. In each market Wema has a reputation of working closely with its customers. Wema is known for tailoring its products to the precise specifications of its customers, regardless of how large (or small) a production series it may be. If you do not see the product your company requires, please contact us and we will work with you to design and manufacture a solution according to your specifications.

As supplier to many industries, each with its own stringent quality requirements, Wema satisfies the relevant international standards. Our goal is to seek continuous improvement of quality and reliability.

Reed Switch Level Sensors

Level measurements are done by series of hermetically sealed reed switches positioned inside the main shaft of the sensor. A float with built-in magnets then triggers the reed switch relays, generating a potential-free Reed Switchresistance with ohm value that increases or decreases according to the fluid level. Output is fully customizable, available as resistance, current, or voltage signals.

The advantage of reed switch type level sender over thick-film swing arm type level sender is the reed switchs durability and reliability. Switches used in the reed switch level senders are able to perform over 50 million actuation cycles, more than 5 times that of thick-film resistors. Additionally in reed switch level senders the float is the only moving part of the sensor, thereby minimizing potential mechanical failures.

The standard level measurement resolutions on our level senders are approximately 0.5(13mm). However, if your level measurement application requires finer resolution, customized senders with resolution as low as 0.18(4.5mm) are available upon special request.

All sensors are fully insulated to protect against spark and voltage inside the tank.

SSS/SSL, S3U, S5U

Our most versatile senders are the SSS/SSL, S3U, and S5U models. These single stainless steel models typically have a NBR 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 1.5NPT threaded mount. These single stainless steel models can be used in water, fuel, hydraulic oil, or diesel.

For special chemical solution applications, please contact us to verify 1) whether you can use the senders with standard NBR float, or would need to order senders with stainless steel floats (more corrosive solutions); 2) the buoyance level of the solution relative the float buoyancy.

High Resolution Capacitance Level Sensors

The high-resolution solid-state level sensor, or Capacitance Level Sensor (CLS), is used to continuously detect CLS fuel level by measuring the capacitance variations as the liquid level changes. The CLS has an integrated filter, contains no moving parts, simple to use, can be easily shortened to fit different tank depths, and the parameter can be conveniently reset and calibrated with an external calibrator. Capacitive technology provides extremely precise and reliable output signals with resolution less than 1mm.

The standard output for the CLS is 0-5V, 0.5-4.5V, or any other voltage analog output. However units with integrated RS232 converter are also available for applications that require digital outputs from the level sender.

With the precision and high resolution of level measurement, the CLS can be integrated into many applications. One of the most common usages is to incorporate the CLS with a GPS tracking system. This allows the user to detect the fuel usage, or possible leaks or theft by remotely monitoring the liquid level with high accuracy.