Our selection of dwyer instruments are widely used in the HVAC industry. Differential pressure gauges are useful devices that can detect the difference of two pressures and how they were applied. A magnehelic gauge is a common differential pressure gauge brand that can measure air velocities. Pressure gauges can be used for a multitude of a sizable machinery with different PSI ranges. We also carry gauge guards seals and accessories, and be sure to check out our pressure and temperature test kits to make sure your HVAC equipment is running efficiently.