This page shows a few selected examples from the areas of process measurement and sensor systems. More examples can be found in the other categories on our webpage, i.e. level sensors, selective audio emission or determination of material properties.
The ultrasonic flow measurement is a contactless, precise and maintenance-free method and has developed to the growth driver in the area of flow measurement. The measuring principle is based on a time of flight measurement in flow direction and in the opposite flow direction. If the sound propagation and the liquid flow points in the same direction, the measured time of flight increases, whereas if the flow and sound propagation is antiparallel the time of flight decreases. Using the difference of both measurands the average flow velocity is calculated.
The need for still more precise, more efficient and also cheaper flow meters or sensors increases steadily. Particularly ultrasound flow sensors offer a great innovation potential for example for the exact dosage of smallest amounts of substances, for the simultaneous identification of the liquids (for instance to avoid misfuellings) as well as for the simultaneous density measurement or mass flow measurement and many more applications.
Due to their ease of maintenance and mechanical robustness, ultrasound measuring systems are increasing in popularity. This is why they're being used for measuring filling levels, flow and increasingly for continuously measuring a substance's concentration or process-monitoring. Therefor the materials properties such as sound velocity, acoustic impedance and absorption are determined and analysed. For example by simultaneously observing the sound velocity and the acoustic impedance the ethanol concentration in a mixture of liquids can be measured
When a liquid contains gas bubbles, resulting dispersion and absorption have a strong influence on the measurement. The researcher’s objective is to develop a new kind of impulse based ultrasound measurement system, which can continuously measure the substance's properties (sound velocity, acoustic impedance, acoustic absorption, …) and at the same time characterizes the gas phase. It is possible to directly measure the size of the gas' bubbles and their volume.
NIR moisture measurement
The knowledge of a material’s moisture content is very important when working or storing free flowing and solid goods (grain, pre-packed food, sand, paper etc.). There are different physical principles which can be used in the measuring process, which all have their individual pros and cons. For a contactless and permanent measurement the infrared reflection method is the best solution. The Measurement Engineering Group, together with REMBE GmbH from Brilon, Germany, has developed the measurement system NIROMM™ (Near Infrared Reflexion On-line Moisture Measurement), which's core is new detector head.
The measurement system has following advantages:
- Use of selective beaming IR-LED
- No moving parts Online-measurement on moving substances
- High measuring rate and accuracy