Temperature
Gauges should not be exposed to excessive heat or cold
since this causes them to indicate incorrectly. Excessive
heat could cause the solder which is used to join the
tube to the connection to melt. Gauges containing
liquids should not be exposed to cold as the liquid could
solidify and damage the tube.
Gauges should be mounted away from heat sources
either via a sufficient length of capillary to keep the
gauge cool, or in the case of steam, fitted with a syphon
tube which is filled with distilled water prior to use