Instrumentation Reference Book, 4th Edition

21.7. Temperature Measurement Considerations

21.7.1. Readout

21.7.1.1. Local Readout

If temperature needs to be measured at a particular point in, say, a chemical plant, what considerations govern the choice of instrument? The obvious first choice to most people is a liquid-in-glass thermometer. However, this requires that one must be able to get close enough to read the instrument accurately. A better solution is a dial thermometer. The type of instrument chosen will of course depend on the accuracy and repeatability required. In general, and especially on bigger plants, local temperature measurement is for general surveillance purposes only; the measurement is probably not essential but is provided as a cross-check on the control instruments to ...