| 摘要 |
<p>The colourimetric temp indicator which does not revert on cooling and can therefore be used for determining temp. at places inaccessible during heating (soldered connexions in generating valves etc) is obtained by coating a dark coloured carrier (usually paper) with a soln (usually in ethanol) of a fatty acid and/or its salt together with a binder (pref. polyvinylbutyral lacquer). On reaching its melting point the solids melt, exposing the dark coloured carrier. Ranges of 60-63 degrees C to 153-158 degrees C can be covered, by using palmitic, stearic acids and/or the Fe, Mg, Co or Na salts of stearic acid.</p> |
