Thermometry dielectric constant

The three modern types of gas thermometry - constant volume gas thermometry (CVGT), acoustic gas thermometry (AGT) and dielectric constant gas thermometry (DCGT) - are presently considered primary . They are based on simple relations between the properties of an ideal gas and temperature T. However, the departure from the ideal behaviour must be carefully considered in view of the desired level of accuracy. This is done by measuring the thermometric property as a function of density. Then the ideal... 

An interesting aspect of dielectric constant thermometry is the small influence of a magnetic field. On the other hand, measurements depend on both the measuring frequency and voltage (see Figs 9.12 and 9.13). Figure 9.13 shows an example of the dependence on frequency of both the dielectric constant and loss for Upilex S [93]. 

B. Fellmuth et al. Dielectric-Constant Gas Thermometry and Determination of the Boltzmann Constant TEMP-MEKO 2004, Cavtat-Dubrovnik Croatia, ISBN number 953-6313-73-1... 

The most frequently and conveniently used gas thermometer is the constant-volume thermometer, which utilizes the changes in pressure to indicate changes in temperature (Guildner and Thomas, 1982). Another type of gas thermometer is the dielectric-constant gas thermometer (Gugan and Michel, 1980). Measurements in this case depend on the change of the dielectric constant with gas density and, thus, are intensive in their nature, in contrast to the extensive quality of regular gas thermometry. A reference temperature is required for the operation of gas thermometers. Recent gas thermometry results (Guildner, 1980) have uncertainties of about 0.002°C associated with them, but such small uncertainties are very difficult to obtain. 

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