Concept
MP-V Air Flow Sensor
The MP-V uses a digital pressure sensor to measure the air velocity pressure signal from the velocity probe in the inlet of the VAV box. The measured value is used by the controller to position the VAV damper actuator for the required air flow.
The sensor is an integrated diaphragm-based pressure sensor, which means that it requires no air flow from the velocity probe.
As there is no air flow through the sensor, the sensor is not susceptible to maintenance and performance issues caused by accumulation of dust and particles in the sensor and tubing, and the error (reduction) of the actual pressure level seen on the test/balance taps of the velocity probe. The sensor does not require maintenance.
The pressure sensor also offers the ability to connect a local digital manometer to the same probe when you want to obtain accurate measurements that can be used for cross-check verifications.
The sensor is factory-calibrated and requires a minimum of field adjustments. Field air balance calibration is typically only needed when adjusting for anomalies and inaccuracies introduced from the local duct and air flow situations.
MP-V controllers with the diaphragm-based sensor support a flow control range from 7.5 to 249 Pa (0.030 to 1 inH 2 O).
The low-flow control depends on the VAV characteristics and conditions beyond the sensor. Stable low-flow control also depends on the stability of the air duct inlet pressure (static pressure at the VAV), the precision and smoothness of the air damper movements, the integrity of the damper gasket and sealing, and the VAV controller program applications.
Hardware Overview
MP-V Controllers
Connecting an Air Velocity Probe to the MP-V Air Flow Sensor