Understanding Air Velocity Sensors

Stainless Steel Pitot Tube, Series 160

Dwyer Instruments, Inc. offers a multitude of sensors for monitoring air velocity in HVAC systems. Some of this instrumentation has a simple construction (Pitot tubes, for example) while others are more complex, such as hot-wire anemometers.

The initial term and first “hot-wire anemometer” was developed back in 1914 by Louie Vesso King. He is also accredited for King’s Law, which mathematically describes heat transfer in air flows using a heated wire. As the air moves over the wire, it causes a loss of temperature in the wire and removes some of the wire’s heat energy. Continue reading “Understanding Air Velocity Sensors”

Mystery Solved! Dwyer Solves the Wall Mount- Relative Humidity Error Problem

Wall mount humidity sensors for building automation system (BAS) applications are produced and sold by several different companies and have a reputation of poor accuracy despite specifications from suppliers. There is a rational reason why these instruments appear to read outside of their stated accuracy, which in turn causes users to be frustrated with the results.

Continue reading “Mystery Solved! Dwyer Solves the Wall Mount- Relative Humidity Error Problem”