This is the second edition of a text first published in 1994, which had its origin in a volume of course notes published for a series of workshops on temperature measurement and calibration that took place in the 1980s in New Zealand. In the first edition, the authors set out to cater particularly for `the beginner with modest experience who wishes to acquire expertise and knowledge quickly'. The text, in fact, was much broader than this and was written for a wide readership that extended from the beginner to experienced scientists and engineers who need a ready reference covering many aspects of temperature measurement and calibration. The authors succeeded admirably in their aim and the first edition provided a welcome addition to the relatively small body of literature devoted to temperature measurement.In the second edition, the main body of the text treating the principal methods of temperature measurement remains largely unchanged. The new version, however, reflects the much greater importance now placed on the formal requirements for traceability and statements of uncertainty. The excellent chapter on uncertainties in measurement has been revised to make it fully consistent with the ISO Guide to the Expression of Uncertainty in Measurement. The chapter on calibration gives essential advice on the application of ISO 17025 General Requirements for the Competence of Testing and Calibration Laboratories. For those engaged in running or setting up a calibration laboratory for temperature measurement, the text is now a mine of useful information.The second edition also contains a new chapter entitled `Use of thermometers'. This is essentially a summary of all the reasons why a thermometer is not giving the right answer! It includes a good discussion on the various mechanisms of heat transfer to and from the thermometer, immersion errors, settling response errors, and the effects of thermal radiation and temperature measurements in non-equilibrium situations. All users of thermometers will find this chapter useful as it brings together material that otherwise is widely dispersed.For the rest, there are chapters on the International Temperature Scale of 1990 (ITS-90), platinum resistance thermometry, liquid-in-glass thermometry, thermocouple thermometry and radiation thermometry. The chapter on thermocouples now includes an extensive account of how a thermocouple works. It is emphasized that the measured thermoelectric potential difference between the ends of a pair of thermocouple wires is developed along those parts of the wires that are in the temperature gradient and that it has nothing to do with the junction provided that there is electrical contact and the junction itself is not in a temperature gradient. The authors quite rightly stress that, unless this is understood, the correct use of thermocouples and an appreciation of their likely source of error are much more difficult. The authors point out that the so-called `laws of thermoelectricity', although perfec...

This is a summary of the Consultative Committee for Thermometry (CCT) Key Comparison CCT-K3, i.e. the comparison of realizations of the fixed points of the International Temperature Scale of 1990 (ITS-90) over the range 83.8058 K to 933.473 K. The differences in the realizations of the various fixed points in this range of the ITS-90 and the uncertainties of those differences are given for the fifteen standards laboratories participating in the comparison.

An analysis of the resistance-temperature relationship for six low-temperature platinum resistance thermometers is carried out to determine the thermodynamic accuracy of the ITS-90 below 273 K. The use of smooth thermodynamic functions in a model equation for platinum resistance indicates that there is a significant deviation of the ITS-90 from thermodynamic values over the range 80 K to 270 K. The deviation is consistent with recent results in acoustic and gas thermometry, namely around 10 mK at 150 K. For this reason a re-evaluation of the existing thermodynamic data on the temperature scale appears warranted.

Some derivations are given for approximations to the energy levels and eigenstates of triplet-state organic molecules in external magnetic fields of such a magnitude that the electron Zeeman interaction is small relative to the intramolecular electron-electron interaction. An exact calculation of the exactly zero external field magnetic resonance spectrum of photoexcited naphthalene is given. Experimental measurements of the zero-field spectrum of naphthalene are presented. The results of the approximate and exact treatments are compared with these results and with other available experimental information.