DILATOMETER Russian patent published in 2017 - IPC G01N25/16 

FIELD: measuring equipment.

SUBSTANCE: invention relates to the field of material research using thermophysical measurements, namely devices for measuring the temperature coefficient of linear expansion (TCLE). The dilatometer comprises a heating chamber with a detachable tube in which the sample to be examined is horizontally mounted and pushers tightly in contact with opposite ends of the sample, measuring mirrors fixed at the ends of the pushers and located outside the heating chamber, a laser and an optical system for measuring the elongation of the sample. The pushers and the sample are mounted each on two symmetrical supports located from their center at a distance of 0.277 of the length of each of them. To create a constant in magnitude and symmetrical pushing of the pushers to the test sample, a clamping system is used. In the optical system, a four-way interferometer including a polarized beam splitter, dividing the laser beam into the working and reference beams, a quarter-wave and polarization plates, two rotary mirrors, two retro-reflectors, four by-pass mirrors for the working beam and a photodetector is used to measure the elongation of the sample. Electrical signals from the photodetector and the thermocouple, which registers the heating temperature of the sample, are transmitted to the PC, where they are synchronously recorded. The dilatometer is calibrated with a sample from the reference material with known characteristics of the change in the TCLE in the required temperature range. For this, elongation of the pushers is determined by subtracting the calculated elongation of the reference sample from the measured total elongation of the "reference sample-pusher" system. The reference sample is replaced by the explored one. When the latter is heated in the same program as for the reference sample, its elongation is determined by subtracting the previously obtained elongation of the pushers from the total measured elongation of the "test specimen-pusher" system. According to the obtained data, the value of the mean integral TCLE is determined.

EFFECT: increasing the accuracy of measuring the elongation of the sample when determining the temperature coefficient of linear expansion of the material under study.

5 cl, 4 dwg