Complex permittivity measurements at 8 6 mm wavelength over the temperature range 1-60 C

This is the authors' abstract. We don't add key points for this paper.

An 8·6 mm microwave bridge has been used to determine the complex permittivity of water over the temperature range 1-60°C to within a standard error of 0·25 in both ' and ". These results indicate that the high-frequency dielectric constant [infinity] varies with temperature from 4·9 ± 0·3 at 1°C to 3·1 ± 0·8 at 60°C, which is a new proposal for water. As with previous investigations, it is difficult to discriminate between Debye behaviour and a small distribution of relaxation times, but the present measurements conform to the latter type of process below room temperature with increasing approximation to a single relaxation time as 60°C is approached. Values of the relaxation wavelength λs, with an error of ± 1-2%, are also given and are slightly lower than those published hitherto.