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.
