Fluid flow measurement unit, e.g. for HVAC applications, has a bypass line with a flow sensor and a main line which incorporates a flow former in order to ensure a linear relationship between pressure drop and flow rate

摘要

Flow measurement unit for a measuring a fluid flow rate has a bypass line (3) from a main flow line along in which there is a flow sensor (9) that derives the flow rate from the measured pressure drop. A flow former (20, 22, 23, 26) is incorporated in the main line to form the flow in the area of the bypass. The seqential zones within the area of the bypass line has a flow shape such that there is an almost linear relationship between the pressure drop over the length of the bypass line and the flow rate in the main line (2).