CMR is the manufacturer and designer of the Velogrid which consists of a duct frame made to measure in increments of 100mm in height and 50mm in width. The CMR Veloprobes are fitted into the frame and are connected to a manifold which provides an average air velocity pressure measurement. The Velogrids are normally mounted in a reasonably straight duct and the air flow generates a differential pressure on the static pressure port (blue) and the impact pressure port (red). The CMR P-Sensor, V-Sensor , DPM-Sensor and the DPC Controllers can be connected to provide a linear volume flow output signal.