Contact thermometer with mercury temp. sensor - has several chambers surmounted by capillaries into which circuit contacts project

摘要

A contact thermometer uses a relatively large amount of mercury in its temp. sensor yet maintains a low time constant. The sensor is immersible in the medium whose temp. is to be measured. Thermometer capillaries are mounted above the sensor to receive the mercury upon heat expansion. Two contacts of an electrical circuit delivering a control signal project into the inner space of the capillaries. These contacts are closed by the mercury rising against the force of gravity. The temp. sensor consists of several chambers around which the medium can circulate. They are spatially connected to receive the mercury and form a space with large inner wall surfaces w.r.t. the vol. of the spaces. Their walls are of a material that is chemically inert w.r.t. mercury and whose heat conductivity is equal to, or greater than, that of mercury.