GB1360861A - Temperature indicator - Google Patents

Abstract

1360861 Thermometer BIO-MEDICAL SCIENCES Inc 23 July 1971 [24 July 1970 4 March 1971] 34720/71 Heading G1D A thermometer comprises a carrier 11 having regions 7 each including an organic solid solution 9 which melts at a predeterminedtemperature. A clinical thermometer includes a series of regions 7, each containing a solid solution melting 0À2‹ F higher than the previous one. Each region 7 has an indicator layer 13 and a masking layer 15 to facilitate visual detection of fusion of the solid solution 9 in the region. The indicator layer 13 may be an absorbent paper impregnated with a dye or pigment, and the masking layer may be an absorbent paper of contrasting colour. Alternatively the dye or pigment may be incorporated into the solid solution. The carrier 11 may be aluminium, copper, silver, gold or stainless steel foil, and protective layers 17, 19 may be of polypropylene, poly (ethylene-terephthalate), nitrocellulose or polyvinyl chloride. A metallic powder may be included in layer 19 to improve its heat conductivity. The solid solution 9 may be one of the following binary systems: p-dichlorobenzene with p-bromochlorobenzene, o-chloronitrobenzene with 0-bromo-nitrobenzene, 1- menthol with dl-menthol, acetophenone with henzophenone, demethyl succinate with dimethyl oxalate, 4-chloropropiophenone with 4-bromopropiophenone, 4-chloro-2-methylaniline with 4-bromo-2-methylaniline, 4-chloroacetophenone with 4-bromoacetophenone, n-butyl sulphoxide with n-butyl sulphone, n-hexane with 2-nondecane, cyclohexane with 2-nondecane, α-chlorocinnamaldehyde with α-bromocinnamaldehyde. A suitable ternary solid solution is p-dichlorobenzene, p-bromo-chlorobenzene and either naphthalene or triphenylmethane.