SU447581A1 - Three-limit thermal indicator pencil - Google Patents

Description

one

The invention relates to the field of thermochemical temperature measurement and can be used to determine the temperature of electronic equipment operating under high-power microwave irradiation conditions.

Thermal indicator sticks, three times less color, at various temperatures, are known, containing a temperature-sensitive substance, consisting, for example, of a mixture of cobalt citrate, pigmentary titanium dioxide and barium sulfate, as well as a binder and hardener.

The purpose of the invention is to expand the range of application and the range of multi-range thermal indicator pencils to temperatures of 280, 370 and 390 ° C and to facilitate operation by reducing the number of strokes applied when changing temperatures of small surfaces.

This is achieved by the fact that the components of the heat-sensitive substance are taken in the following ratio to the total weight,% cobalt citrate 10.0-11.0, grade A titam dioxide 5.0-6.0, and barium sulfate 15.0-16.0. Synthetic resin lacquer, wax and stearin are used as a binder and hardener.

One of the possible variants of the thermal indicator pencil has the following composition,%:

Cobalt citrate 10-I Titanium dioxide 5-6 Barium sulphate15-16 Synthetic resin 15-16 Ethyl or butyl alcohol (other solvents and thinners are possible) 15-16 Stearin 20-21 WaxExtra

The proposed temperature indicator has good adhesion to metal, glass, ceramics, plastics.

The surface to which the stroke is applied with a pencil should have a temperature of about + 40 ° C.

When the temperature rises from the initial to the critical for 2 minutes and the duration of the exposure to the critical temperature of 30 seconds, the thermopencil gives three color changes at the following temperatures: 280 ° C from light lilac to beige; 370 ° С from light lilac to black through beige;

390 ° С from light lilac to gray through beige, black.

Other parameters of heating mode lead to a change in transition temperatures.

For example, the heating rates of 200 degrees / min correspond to the following junction temperatures from, ew; d air-1: shine: at 315 ° C — beige; 4 th 4 0 °:; - black, at 410 ° C-

Gray:.

Pr and cn 1 and thermal 1 (the effect of the changed color is preserved - the thermal pencil is irreversible.

The presence of magnetic fields and high power microwave radiation do not affect the transition temperature.

Subject invention

Three-limit thermal indicator pencil containing heat-sensitive

a substance consisting of a mixture of cobalt citrate, pigment titanium dioxide, grade A, and barium sulphate, a binder and hardener, characterized in that, in order to expand the range of application and the range of multi-range thermal indicator sticks at temperatures of 280, 370 and 390 ° C and facilitate operation , the components of the heat-sensitive substance are taken in the following ratio to the total weight,%: citrate cobalt 10.0-11.0, pigment titanium dioxide A grade 5.0-6.0, barium sulfate 15.0-16.0.