Density and level sensors

Density and level sensors

Precise control of all equipment and material parameters is key to achieve a high-quality and reliability in all material-processing industries.

Level and density sensors are indispensable instruments in this environment and ScioSense sensor interfaces help to enhance the range and performance.

Ultrasonic time-of-flight measurement translates the travel time of an ultrasonic burst through a liquid into physical units. 

For a known fluid the travel time from the bottom of a tank to the surface of the liquid filling can be directly translated into fill level information. On the other hand, the similar measurement for a given and fixed distance can give information about the speed of sound in the liquid which then might be translated into a concentration information. An example might be to measure the percentage of soap in water in the tank of a cleaning machine. 

ScioSense ultrasonic flow converters manage the complete measurement process and can translate the results into the requested physical unit. The high precision of the time-of-flight measurement allows to get millimeter precision in level measurements or percent precision in concentration measurements. 

Application diagram level

Figure 1: Capacitive level sensing

Capacitive level sensing measures liquid levels by measuring changes of capacitance in potentially simple sensing elements, made just from a PCB. When working with plastic containers the sensing elements might be mounted from outside to the tank wall or even with an air gap.
Our PCAP04 capacitance-to-digital converter reaches up to 20 bit resolution, which allows to measure capacitance changes even through 1 cm of plexiglass. The on-board DSP can process temperature compensation and linearization and translates the capacitance change directly into a level information.

AS6031 Ultrasonic Flow Converter

Design requirements / challenges

Design requirements / Challenges:

  • Wide measurement range
  • High precision
  • On-chip linearization & compensation