2.1 Liquid-in-Glass Thermometers
Liquid-in-glass thermometers are based upon the temperature dependent variation of the volume of the liquid which is used . The thermometer consists of a liquid filled bulb connected to a thin capillary with a temperature scale as shown in Figure 2.1 . Assuming that the bulk volume, Vb, is much greater than that of the liquid contained in the capillary, the volume variation, AV, of the liquid corresponding to the measured temperature variation, d6, is: AV = V/3.;AO (2.1)
where /3a is the average apparent coefficient of cubic thermal expansion of the thermometric liquid in the given glass....