Fluid Management Sensors

Strain Measurement Devices is known for our state of the art Load Cell technology, but our engineers have been designing an ever expanding sensor portfolio that monitors, measures and controls fluid. Fluid management sensors are a diverse collection across all of Strain Measurement Devices’ product lines. Customers are asking for sensors that can monitor fluid systems”noninvasively” (without contacting the process fluid). SMD has developed non-invasive fluid monitoring sensors to measure flow rate, totalized flow volume, bubbles-in-liquid, occlusions (blockage) in fluid flow tubing, internal tubing liquid pressure, liquid level in bags and vessels, and weight or weight change over time for flow rate. 

Ultrasonic Fluid Technology

Fluid management and control sensors offer a variety of options in what and how your application is monitored. Many SMD product lines featuring ultrasonic technology, measurements can be done through non-invasive means protecting the integrity of any critical fluid. Ultrasonic fluid sensors operate by emitting pulses of ultrasonic sound (sound inaudible to humans) between two crystals. By monitoring these signals and applying custom algorithms, SMD ultrasonic sensors can monitor flowrate, totalized flow volume, bubbles, and liquid level. Since ultrasonic sensors do no need to touch the liquid they are ideal for difficult or corrosive fluids, such as acids, waste water, and others.

Ultrasonic Flow Meters technology exhibits superior time resolution designed for flow measurement in tubes.  SMD clamp-on flow sensors measure flow rates with exceptional accuracy and turn down ratios. Paired with the touch screen electronic FlowDAQ system. Disposable ultrasonic In-Line flow sensors are also available for smaller tubing (< 1/4″ OD). The disposable in line sensor is ideal for applications requiring tight accuracy at flow rates. Another flow meter sensor offered is the ultrasonic In-Line Flow Meter sensor.

 Bubble Sensors use proprietary digital noninvasive ultrasonic bubble sensing technology. The air-in-line detector allows for precise bubble size calibration for a range of fluids, allowing extremely accurate bubble detection. Air in line can be detected as small as one micro-liter in a wide variety of fluids and tubing. Using a proprietary control board integrated inside the sensor housing, we monitor signal strength until the bubble disrupts the signal. With a rapid sampling rate of 4000 Hz, SMD bubble sensors can reliably detect even the smallest bubble traveling at a high rate of speed. Custom characteristics can be provided for OEM users, many factors can be customized for your specific application needs.

Ultrasonic Level Sensors are ideal for applications where continuous level measurement is required. Time of flight of the sound signal is measured between the sensor and air-liquid interface. Alternatively, point level sensor float switches are adept at measuring when liquid levels are above or below a certain point. Horizontal, Vertical, Multi-level switches and fully customizable liquid level sensors are available. A full Liquid Level sensor guide is accessible on our sister site: fluidswith.com

Force/Pressure Sensors and Fluid


Pressure and Occlusions sensors offer many benefits to fluid management systems. Occlusion sensors can be used to detect pressure build up in tubing, indicating the flow in the tube is blocked. At SMD Sensors our engineers are able to combine standard ultrasonic fluid technology with our thin film, miniature occlusion sensors. Combined small housing options allow for multiple sensors in a compact unit: Combined Bubble and Occlusion housing unit.

Scales are used in a number of ways when it comes to fluid management applications. Examples include our IV Bag hanging scale which features an S251 Load Cell to weigh IV bags for accurate liquid levels. Also reagent waste bags being placed in our low platform, overload proof scales to keep contamination at a minimum. Mass weight over time to determine fluid flow rate is another application where fluid can be monitored and measured by low platform scales.

Contact Us and a member of our team will be in touch to discuss your challenges and design ideas.

Related Blogs: