Answer / b0nz0

There are numerous types of both gauges.
The most common type of pressure gauge is the Bourdon tube.
This consists of a 'C' shaped tube closed at one end. When
pressure is applied to its open end, the tube tries to
straighten due to its oval cross section. This movement is
amplified by a mechanical linkage and gears to give
sufficient movement on a pointer.
One type of temperature gauge also uses a similar principle
where the Bourdon tube is part of a sealed system which is
filled with a fluid. The fluid expands with increasing
temperature causing the pressure in the sealed system to
increase.
Another common type of temperature gauge is the bi-metalic
gauge which depends on the difference of expansion between
two dissimilar metals. The bi-metalic element is
constructed as a helix to give sufficient rotation of the
pointer.

Answer / nirmal

pressure gauge is working on Hooks law,for temperture RTD
works on Resistance temperature detective and thermocouple
works on seebacks effect by comparing hot and cold junction.

Answer / mian hassan

Most standard dial type pressure gauges use a bourdon tube-
sensing element generally made of a copper alloy (brass) or
stainless steel for measuring pressures 15 PSI and above.
Bourdon tube gauges are widely used in all branches of
industry to measure pressure and vacuum. The construction
is simple yet rugged and operation does not require any
additional power source. The C-shaped or spirally wound
bourdon tube flexes when pressure is applied producing a
rotational movement, which in turn causes the pointer to
indicate the measured pressure. These gauges are generally
suitable for all clean and non-clogging liquids and gaseous
media. Low pressure gauges typically use an extremely
sensitive and highly accurate capsule design for measuring
gaseous media from as low as 15 INWC to 240 INWC (10 PSI).
Digital gauges use an electronic pressure sensor to measure
the pressure and then transmit it to a digital display
readout.

Answer / aftab ahmed mazari

Both work at pressure but temperature gauge has filled system and its filled liquid expands with the rise of temperature.So that expansion of liquid gives pressure to gauge which is connected via capillary.

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