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The suitability of vacuum tungsten blackbody lamps as secondary standard sources in photoelectric pyrometry has been investigated. It has been found that although the sources are stable when operated for long periods at temperatures up to 1625 °C they will not maintain calibration when physical strain is introduced into the tungsten tube or supports, for example, by vibration of the lamp. All changes detected in calibration of lamps have been accompanied by changes in their electrical resistances, and therefore this parameter can be used as a monitor of calibration stability. Variations in resistance at the gold point of 0.1% produce significant changes in calibration. The effect of pin temperature on the lamp resistance and spectral radiance temperature are given. When precautions are taken in handling, mounting and storage to minimise the introduction of strain in the lamps the uncertainty in their calibration at the gold point is less than ±0.1°C.

The frequency shift in cesium beam atomic frequency standards resulting from the second order doppler shift is described in terms of a truncated Maxwellian velocity distribution in the atomic beam. A means of establishing the upper and lower limits of the atomic velocities accepted by the standard, based on fitting of experimental and calculated Ramsey resonance patterns, is outlined. A detailed analysis of the influence of both the velocity distribution and the exciting power level is given, and it is shown that an asymmetric resonance results, with asymmetry greatest for a full Maxwellian distribution. Results are given for the NRC 2.1 m cesium standard, Cs III. An increase of the second order doppler shift correction for Cs III from 0.003 Hz to 0.0072 Hz is required, and the effect of this on the NRC UTA time scale is discussed.

The experimental realizations of the normal boiling point of oxygen maintained in several national standards laboratories are compared.

The "International Temperature Formula" generally in use since 1910 does no more correspond to the cells and the demands of precision of today. Therefore a new equation was determined for the relation of the emf to temperature from 10 to 30 °C based on very exact measurements of emf and temperature: E_tE₂₀ − [39,78 (t − 20) + 0,936 (t − 20)² − 0,0086 (t − 20)³] · 10^-6.

New absolute energy measurements of α-particles from 20 natural and artificial emitters are reported, some of which are first absolute values. The uniform field 180° magnetic spectrograph is described in detail. Accurate length and field measurements and line shape extrapolations have been given special attention. A detailed error analysis is presented.

The paper cited in the title by Winkler, Hall, and Percival (WHP) documents some important aspects of the widely referenced United States Naval Observatory (USNO) Time Scale system. We augment the text of WHP regarding the mutual synchronization to within 5 μs of the Time Scale, UTC(USNO), with another widely referenced time scale, the National Bureau of Standard UTC(NBS) Time Scale. We show that some of the information available to WHP can be utilized to give even more precision to the USNO Time Scale system and that some of that information has been improperly interpreted causing some errors by WHP in their conclusions regarding time scale precision, clock weighting factors, and drift in rate of the time scale.