Development of a stable transfer standard thermometer. II vibration test of prototype models

For pt.I see ibid. (2002). Standard platinum resistance thermometers (SPRTs) are delicate against mechanical shock and vibration. It is empirically well known that even a little mechanical shock causes easily the resistance change equivalent to more than some tenth of millikelvins in temperature and that strong shock causes the change of some millikelvins. This resistance instability become one of the most effective factors of uncertainty in precise temperature measurements. To reduce this uncertainty we have developed mechanically-stable SPRTs and evaluated the stability of them by vibration test. The results showed the significant stability better than 1 mK which is sufficient for the usage as traveling transfer thermometers. In the present study mechanical characteristics of thermometers were evaluated only in the vicinity of room temperatures, the triple point of water and gallium point temperatures. Thermal stability which is necessary to be checked to use the SPRTs at higher temperatures have been discussed later.