DesignSpark Electrical Logolinkedin
Menu Search
Ask a Question

19 May 2016, 12:46

Ultrasonic Sensors for fluid level control

Process industries and the need for fluid control

Fluid control covers a great number of areas within the process industry. The need for level monitoring plays a significant part in this and employing the correct sensor technology is paramount.

There are a number of ways to control, monitor and measure liquid levels within process and storage tanks. One of the most common, ultrasonic technology, relies on echo detection, where pulses from the sensor are reflected back from the surface of the measured medium and the time taken to receive the echo can be calculated as distance. In storage tanks this time can actually be calculated as the fluid level. 

NB: Ultrasonic technology detects most materials not just liquids.

Threshold points for high and low levels can be measured easily to allow for planned replenishments.


Maintaining the correct operational level in industrial processing tanks is important, both for costs and operating efficiencies. Order a re-fill too early and there is the chance the re-fill vehicle returns with half the load, this is uneconomical and the cost has to be absorbed. Alternatively ordering too late, when the tank is nearly empty causes a heightened risk of contamination from particles and sludge gathered at the bottom of the tank, if this happens then a de-contamination of the whole process and storage tanks could be required. Even a simple shut down is costly, usually in the £1000’s per minute.

Consider the operating environment and fluid


Acid and caustic solutions, present their own problems, the sensor selected must be corrosive resistant. Also it’s common that these tanks are placed within hazardous environments. This is where ATEX approved ultrasonic sensors come in, being corrosive resistant and approved for use in hazardous areas they are ideal for monitoring chemical levels in potentially explosive environments.

The Vega SN61.CXAGHKMX (613-3415)  level transmitter with HART communication is ideal as a low cost solution for fluid level monitoring and can be retro-fitted to existing tanks easily and quickly. Together with height, distance and volume, flow in open channels can also be measured.

Fluid level, volume and flow can be measured using Ultrasonic Sensors


Typical application for ultrasonic level sensors include;

    Buffer Tanks, Open flow Water and waste management, Agricultural Silos, Oil and Gas, Food and beverage.

For more on Ultrasonic level sensors check these brands;




Pepperl + Fuchs


Favourite things are Family, Music and Judo. Also, I have the ability to retain and quote useless facts, something that pleases me but can annoy others. My engineering hero - Isambard Kingdom Brunel

19 May 2016, 12:46