Book - School of Science and Technology

Commissioning and measurement 473SensorconnectionsFunctionselectorDigitaldisplayMin/Max/AverageswitchesFigure 16.34 Digital multi-purpose instrumentvariable. Some makes are capable of giving dual output for two measured variables,together with minimum, maximum and average of readings taken over a period of time.Typically, humidity, temperature, air speed, pressure and rotational speed measurementare available by fitting different heads to a single instrument, as in Figure 16.34. Withmemory facilities to provide functions such as datalogging, input codes for locationreferencing and volume flow rates calculated from velocity measurements, this form ofinstrument is very convenient for site use.