Liquid Level Product Information

SST liquid level sensors can operate in high temperature to extremely low temperature conditions. The maximum range is -40 to +125C.

Our liquid level sensors are point level (digital) not continuous (analogue). They detect the presence and absence of fluid.

There are two preferred ways to mount our optical liquid level sensors. Mount the sensors at the side or the bottom of your application to allow liquid to run off the sensor. If the sensor is pointing downwards, liquid may still be on the sensor tip for a longer time and the sensor will assume it is in liquid. For one off alarm applications, mouting the sensor at the top of the application would be ok.

Our smallest liquid level sensor is ourLLC500, available in analogue or digital with 4 wire versions. Our LLC500 can run at very low power (3V) and has fast response times (within a few m/s from exposure).

Our optical liquid level sensors can only handle up to 50% Ethanol. Any higher, then it becomes almost pure alcohol. SST have tested our sensors in various fluid types and a list of these can be found on our Liquid Level Application Note. If your fluid type is not listed, it is not to say our sensors will not work in your applications fluid type, all we suggest is to test our sensors in the liquid.

We do not have sensors as such that can measure exact level. Our sensors can only detect the presence and absence of fluid. For continous level measurement, install a number of our sensors at specific levels in the application, giving you the acuracy you require.

At SST we manufacture 120,000 optical liquid level sensors per annum.

The types of applications we would not recommend to use our liquid level sensors, are applications where milk, emullsion and soapy water are present.

The difference between the LLC500A3 and the LLC500D3 is; the D3 version contains a lot more electronics; voltage regulator, reverse polarity protection, amplifier etc. This means when you apply a supply voltage of anywhere between 5 and 12V, the output will either be zero or equal to the supply voltage.

The A3 range is much lower cost because it contains inly the opto components. It has no protection components and you have to add external resisitors and a circuit that takes analogue voltage from the sensor and decides whether that means the sensor is in air or liquid.