Field-Changeable Constant Power/Constant Temperature Technology Is Here
With thermal mass gas flow meters, there have always been two measuring techniques, constant power (CP) and constant temperature (CT). Both of the techniques are viable, popular, and have both advantages and disadvantages. Historically the trade-offs were about range, response times, sensor life, and susceptibility to moisture in the gas and power consumption. Over time, all the reputable manufacturers continuously tried to improve their products to overcome some aspect of their preferred technique’s short-comings.
But what if you just combined both techniques in the same flow meter, and made it field changeable. Should than the actual installation conditions not be as expected? Wouldn’t that be the ultimate solution? Today, this “both” techniques is a reality in Fluid Components International’s new ST80 thermal flow meters. The ST80s incorporate both FCI’s patent-pending AST™ technology (Adaptive Sensing Technology), which is a hybrid drive that combines both CT and CP together, and CP mode. AST utilises fast responding CT technique at lower flow ranges and seamlessly, and automatically, shifts into CP mode at higher flow rates. This AST hybrid technique then provides a faster response, wider flow range and low power consumption in the same flow meter. And, if the application contains any moisture or where the AST response time is too fast, the ST80 can be set to run in the better application matched CP mode only.
So, if you are specifying, designing or using thermal flow meters, you no longer need to make product selection. Trade-offs based on the measuring technique with ST80 are no longer an issue. Further, if your actual application and installation could be different than expected, with the ST80 you can change the measuring technique between AST and CP modes in the field, to adapt to your discovered, actual installed conditions.
