AMPULE OF DEFINED TEMPERATURE POINTS OF HIGH RELIABILITY AND METHOD FOR CALIBRATION OF SMALL-SIZE AND MINIATURE PRECISION PLATINUM RESISTANCE TEMPERATURE CONVERTERS WITH METALLIC BODY OF LENGTH OF 250 mm MAXIMUM, WITH THIN FILM AND WIRE SENSITIVE ELEMENTS INTENDED FOR APPLICATION OF HIGH-PRECISION TEMPERATURE MEASUREMENTS IN SMALL OBJECTS

FIELD: measurement; test.SUBSTANCE: invention relates to measuring technology and can be used for calibration and verification of precision small-sized and miniature resistance temperature converters, as well as for ensuring reliability of high-precision temperature measurements in small objects due to ability to control their stability before performing high-precision measurements and experimental studies in various fields of science and technology in the range from 0 to 250°C. Ampoule for reproducing defined temperature points of melting metals, made of a metallic glass, a thermometric substance, containing a thermometer pocket, providing a minimum air gap between the thermometer body and inner walls of the thermometer pocket, is claimed. Thin layer of fluoroplastic coating with thickness of not more than 80 microns is applied on the inner surface of the metallic glass, and the thermometer pocket is made of brass with a high thermal conductivity coefficient exceeding the thermal conductivity of the fluoroplastic. Moreover, the ampoule additionally comprises a metal retainer, a gasket and a nut with threaded holes for adjusting screws, and also includes a silicone gasket with a central hole to prevent convection in the thermometer pocket and a silicon gasket to fix the thermometer pocket. Calibration of a small-sized thermal converter is performed by the method of phase transition of pure metals during reproduction of the Ga, In and Sn melting curves in small ampoules heated in a portable temperature calibrator. Output signal of the thermal converter connected to a precision microprocessor-based temperature meter is continuously measured and recorded. Melting process is reflected as a melting curve on the display. Calibration procedure is performed so that measurement and recording of the output signal of the thermal converter continues for the entire time during which the complete melting curve is realized with clearly defined regions corresponding to the start of heating and the subsequent horizontal portion corresponding to the melting of the metal and the region, corresponding to the end of melting.EFFECT: technical result is reduced labour intensity of the calibration procedure for small-sized and miniature thermal converters intended for precision temperature measurement of small objects, and increased accuracy of individual calibration of thermometers for measuring the temperature of small objects by using the method of melting curves of pure metal