Fs – flow sensors - Import export

Large heat and flow meters are often used continuously for decades after an initial calibration at external test benches. A recalibration of these meters within their actual operation conditions was not possible so far. In the best case scenario those flow meters are unmounted and recalibrated on an external test bench. Drawback of this method is an interruption of supply in addition to its already high costs. Furthermore, calibration conditions can differ greatly from actual operation conditions compared to test bench conditions, so even if calibrated, the measurement uncertainty in operation remains fairly unknown. This often leads to more difficult fluid distribution optimizations and leaves billing fairness to a gamble. More precisely measured values of flow sensors may uncover hidden saving potentials within the fluid distribution system and allow more exact performance indicators, improving energy efficiency.

The function of the flow sensor is based on the calorimetric principle. The probe is heated up from the inside a few degrees Celsius in relation to the flow medium, in which it protrudes. When the medium flows, the heat generated in the probe is dissipated through the medium. The temperature within the sensor is measured and compared with the likewise measured medium temperature. From the obtained temperature difference the flow state of each medium can be derived. These sensors are applied in areas such as monitoring of cooling systems, ventilation systems, pump dry running by checking the presence of liquid or gas flows.