FLOW RATE MEASURING UNIT AND FLOW RATE CONTROL UNIT

A flow rate measuring unit, comprising a housing, which is composed of at least two housing parts that can be connected to one another and in which a flow passage extends, which branches off into a measuring channel branch and at least one bypass channel branch, wherein a substrate comprising a sensor system is disposed in the measuring channel branch. According to the invention, the flow passage includes a channel widening chamber in which an insert plate stack composed of at least two insert plates is disposed, which each include at least one plate-longitudinal recess extending in the longitudinal direction as the measuring channel branch and/or as the bypass channel branch. The insert plates are provided as insert parts for the channel widening chamber.