Chapter 16 – Flow Measurement

Publisher Summary This chapter observes flow rate that could be measured either as mass flow rate or volume flow rate. Flow rate calibration is performed by measuring the time taken, starting from an empty tank, for a given volume of liquid to flow into the vessel. Because the calibration procedure starts and ends in zero flow conditions, it is not suitable for calibrating instruments affected by flow acceleration and deceleration characteristics. Alternative versions with more than one U bend also exist to cater for situations where an even longer flow path is required. Inside the tube is a hollow, inflatable sphere, which is filled with water until its diameter is about 2% larger than that of the tube. Pipe provers are particularly suited to the calibration of pressure-measuring instruments that have a pulse type of output, such as turbine meters. In such cases, the detector switches in the tube can be made to gate the instrument's output pulse counter.