Thermometer - Pressure Gauge Plant

Abstract

With the development of industries, various measuring instruments have been produced to minimize errors and strains originating from an instinctive judgement of all phenomena based on human sight, tactile sense, auditory sense, olfactory sense and the like. The manufacture of such measuring instruments, requiring a high degree of precision, is an industry which needs relatively extensive human labor and precision technologies. Among them, comparatively easy and of long tradition are thermometers in addition to pressure gauges, electric measuring instruments and other speed measuring instruments. First of all, the principle of temperature measurement is based on the expansion and contraction of materials depending upon temperature changes, the thermometer being an application of this principle. Glass thermometers and Bourdon tube type thermometers are based on the application of thermal expansion of alcohol or mercury, while the bimetal is based on that of thermal expansion of metals.