Solid state temp. probe - consists of metal granules embedded in insulating carrier body

摘要

A temp. measuring device (1) consists of a probe (2) comprising a carrier body (3) of solid material in which are embedded particles (4) which are in contact with one another and with electrodes (5, 6) attached to the carrier body. The particles are composed of a material which has a higher conductivity and a higher expansivity than those of the carrier material, so that an increase in temp. causes the resistance between the electrodes to decrease. Suitable materials for the carrier body are insulators such as plastics, glass or ceramics. The embedded particles may be tungsten granules of 4mu m to 40mu m. The principle on which the device is based may be used for a pressure probe for use in high pressure vessels.