An Absolute Standard Barometer by M. Yoshitake, I. Shimizu, and K. Takeuchi

[摘要] An absolute standard barometer recently installed at the Japan Meteorological Agency, Tokyo, is . described. It is essentially a syphon barometer made of glass tube 30mm in internal diameter. The two mercury meniscuses can be equally formed by operating the mercury reservoir hydrostatically connected with the mercury column. The vacuum in the space above the mercury is measured by a Geisler tube. The barometric height is read measuring the position difference of two meniscuses by means of a standard scale and a cathetometer. The average temperature of the mercury column is determined from the readings of two thermometers hung on the mercury column. It was intended that the accuracy of a single reading of the barometer should be in the order of 0.OlmmHg, while in practice, it is found that the standard deviation of errors included in the observed values is 0.03mmHg. The result of its comparison with the present DMA's standard barometer gives that the mean correction of the JMA's standard in relation to the new absolute standard barometer is -0.20mmHg.

[学科分类] 大气科学