Flow measurement is part of the metrological determination of a volume flow Q or mass flow m=ρ∙Q. This is done in dependence of a measuring cross section A of a closed pipeline or an open channel.
The flow measurement can be carried out on any fluid, such as cooling lubricants, and is used in a wide range of applications. Depending on the measuring and evaluation method, flow meters are used in power and work machines, waste disposal technology, process engineering, chemical production processes as well as air conditioning and ventilation technology. A further area is the monitoring, control and regulation of coolant and lubricant circuits on, for example, CNC machines for machining.
A distinction is made between two measurement methods. On the one hand, there are the direct measuring methods, where only one single measured variable is required to determine the flow rate. On the other hand, there are the indirect measuring methods, where one or more additional quantities are known or have to be measured in addition to the main quantity.
Overview: Flowmeters and their functions
Flow and volume measuring devices can be divided into two main groups. The first main group consists of flowmeters for open channels, the second main group of flowmeters and flowmeters for closed pipelines.
In this work only measuring instruments for closed pipelines are considered and described in the following. In particular, the flow meters relevant for a grinding process are discussed. An overview of the sensors is given in Table 2-4.