How calorimetric flow monitoring works

How calorimetric flow monitoring works

Calorimetric methods for flow monitoring are becoming increasingly important. We would therefore like to remind you of the advantages and preferred applications of the "calorimetry" measurement principle.

Calorimetric methods for flow monitoring evaluate the heat emission of a heated sensor element to a flow medium. A sensor protruding into a medium is heated up by a few degrees compared to the medium.
The speed-dependent cooling of the sensor by the flowing medium leads to a change in energy consumption by reheating the sensor, since the temperature difference between the medium and the heated sensor is regulated to a constant value. The heating power required indicates the existing flow rate. The physical measured values ??are converted into a switching signal by evaluation electronics.

Advantages of the calorimetric method
Calorimetric flow monitors work without moving parts. The sensor elements are solid, pressure-resistant and work very reliably up to temperatures of 120 ° C.
Appropriate approvals are available for use in hazardous areas.

Applications of calorimetric methods
The devices are used to monitor liquids and gases. They are particularly robust, reliable and insensitive to interference.

Examples: Monitoring of cooling circuits, dry running protection of pumps, coolant monitoring of machine tools, for welding robots, in solar energy generation, for filter monitoring, monitoring of suction and ventilation systems.
Devices made of PTFE, Hastelloy and metal-ceramic are available for aggressive media.


Kalorimetrischer Strömungswächter ST, Auswertegeräte SKM und SKZA monitoring unit consists of a sensor element and a separate evaluation device (sensor ST, evaluation unit SKZ,  SKM or SZAb analog, SZAb relay).



Kalorimetrische Durchflusswächter / Strömungswächter SN und LNAs an inexpensive compact version you will find sensor element and evaluation electronics in one housing (type series SN… and LN… for air).




Flowmeter / flowmonitor SDN 552Compact versions with volume flow display: Types SDN…