Robust Liquid Level Switches

Preventing expensive damage, flooding or run dry operation in level control systems such as monitoring fuel tank levels in off-road construction vehicles and protecting valuable equipment and preventing service interruption by alarming systems when liquid is somewhere it shouldn’t be such as outdoor telecommunication enclosures are just some of the common applications where SST (UK) Sensing’ liquid level switches are used with great success.

Designed and manufactured by SST, the cost effective, single point optical liquid level switches are the product of choice when reliability, durability and fast response is required.

The liquid level switches are available in a range of sizes, materials, housing styles and electrical connections in order to meet the demands of customer application requirements. The robust point level switches detect the presence or absence of almost any liquid type; oil or water based and depending on the application, can be under extreme environmental conditions.

The type of housing material offered by SST is therefore crucial and depends entirely on how compatible the liquid level switches are to the environmental conditions they will be exposed to. SST’s liquid level switches are available in Polysulphone, for less corrosive and damaging fluid types such as water, bleach, butane; Trogamid, for more hostile liquids such as acetone, diesel fuel and heating oil and more recently have been approved for direct food contact in the European Union; Tritan and Glass for aggressive industrial chemicals and where operation in extreme, high temperatures is required.

The operating principle doesn’t change regardless of what housing material the customer selects. When the switch is in air, the infrared light inside the sensor tip is reflected back to the detector. When in liquid, the infrared light is refracted out of the sensor tip, causing less energy to reach the detector. It’s as simple as that!

SST’s liquid level switches are unlike other technologies, they have a long operating life, low sensitivity to ambient light and are not affected by foam when in air, or small bubbles when in liquid. Used as an alternative to float switches but without the worry of unreliability caused by moving parts as they are solid state. They are compact, only protrude a small distance into the application and are able to quickly detect small amounts of liquid. Their ability to function in wide operating temperatures and harsh liquid media for long periods of time result in a very robust switch.

SST understand that customer needs vary and can be very specific. If the standard range of liquid level switches do not meet the customers’ specifications, SST offer customisation on any of their sensor products in order to meet customers’ exact requirements. Whether that be adding or modifying electronics and software, changing outputs, adapting housing or thread styles, adding cabling, connectors or environmental protection, SST consider all options to ensure the customers’ requirements have been met.