On the Development Prospects of Liquid Manometry in the Field of Low Absolute Pressure (0.1–1 000 Pa)

The article describes the principle of operation of a laser interferometric oil manometer from the GET 101-2011 – State Primary Measurement Standard for the pressure unit in the field of absolute pressure in the range 1 · 10 –1 ÷ 7 · 10 5 Pa and its error budget. The article compares the metrological characteristics of the laser interferometric oil manometer with foreign analogues based on the results of international key comparisons. The problems of measuring low absolute pressure in the range of 0.1–1 000 Pa using the laser interferometric oil manometer and possible solutions to these problems are considered. A study of the influence of degassing and compressibility effects on the density of the working fluid of the laser interferometric oil manometer is described, and an analysis of the research results is presented. The idea of increasing the resolution of pressure measurements using the laser interferometric oil manometer is described. An analysis of the possibilities of measuring pressure using the laser interferometric oil manometer is carried out, provided that it is equipped with an optical interferometric device with phase modulation in order to increase the resolution of the pressure manometer and taking into account the research results of the physico-chemical properties of the working fluid of the pressure manometer.