Pyrometers Classification and Radiation Laws
Classification of Pyrometers
The simplest and oldest non-contact way of estimating the temperature of a radiating body is by observing its colour. Table 8 .1 summarises the relationship between temperature and colour . Using this method, experienced practitioners can estimate temperatures over about 700 °C, with a precision sufficient for simpler heat-treatment processes . This is shown in a witty way in Figure 8.1, which is taken from Forsythe's paper (Forsythe, 1941) . It was presented at the historical Symposium on Temperature in November 1939, a symposium that was a milestone in further development of thermometry...