TEMPERATURE INDICATOR USEFUL AS A STEAM TRAP MONITOR

摘要

There is disclosed a temperature indicator particularly useful as a steam trap monitor. The temperature is indicated through the action of a composition of matter placed on an absorbent layer and formed of (1) a solvent made of substance(s) adapted to change from a solid state at substantially a predetermined temperature to a liquid state and (2) an indicator system formed of substances different from the solvent and which are soluble in the solvent when it is in the liquid state and which can change color visible to the naked eye when the solvent passes from the solid to the liquid state or from the liquid to the solid state. A representative indicator system is a mixture of bromochlorophenol blue and ethyl red and a representative solvent is .alpha.,.alpha.'-dichloro-p-xylene. The absorbent layer containing the temperature indicating composition is sandwiched between a transparent tape for viewing purposes, a layer of adhesive, and a paper backed foil. Another layer of adhesive is used as the outer layer for attachment to a steam pipe or the like.