SU1434341A1 - Apparatus for differential thermal analysis - Google Patents

Abstract

The invention relates to the field of thermophysical measurements, in particular, differential thermal analysis. The purpose of the invention is to improve the measurement accuracy. The device contains in the metal block a working and measuring cells fixed on the gauges, which are fixed by second ends in the block. The unit is placed in a heat shield and has thermal contact with it around the ring at the point of contact of the meters with the unit. The heat shield thus focuses the heat flux on the annular part of the block in the middle of its transformation into the radial part, which compensates for changes in the temperature of the block and the ends of the meters. 1 il. c; b

Description

; The invention relates to a measuring technique and can be used to measure the heat and temperature of phase transformations and heat chemical reactions in a continuous heating or cooling rocket (temperature scan),

The purpose of the invention is to increase the accuracy of measuring the heat capacity and heat | effects that occur in the process of changing the temperature of a substance,

. The drawing shows a diagram of the device.

I The device contains a metal | block 1 with a cavity 2, in which | along the axis there is a working cell 3: with a capsule 4 and a lid 5 and a reference: cell 6 with a capsule 7 and a clamp 8,

(meters 9 and 10 temperature differences 20 clause) cells 3 and 6 comes through

1 between the block and the cells, the heat shield 11, in which the holes are closed by the plugs 12 and 13 as well as in the block by the plugs 14 and 15, intended for loading samples. 25 I Measuring instruments 9 and 10 are strictly identical in sensitivity and heat conduction in such a way that their ends facing the heat conduction block 1 are in close proximity to one the other; and the other ends facing the cells; 3 and 5 are spaced apart relative to the other. The heat shield 1 surrounds the heat-conducting metal block -j: 1 and has thermal contact with it on the annular surface in the middle part of the place where the heat conductor, 1 metal block 1, has heat contact meters 9 and 10 40 temperatures. They are electrically: interconnected in a differential circuit and connected to a recording device. (Not shown)

The total heat capacity of the cell 3 45 together with the capsule 4 and the lid 5 is the same as the total heat capacity of the cell 6 together with the capsule 7 and the lid 8.

meters 9 and 10 times the temperature. A temperature difference arises between the heat-conducting unit 1 and each of the cells 3 and b, and the emf leads to the measuring device, the emf through the differential circuit enters the recording device.

Formula

e n n

A device for differential thermal analysis, comprising a heat-conducting unit, a working and reference cell and temperature difference meters between the unit and the cells, connected in a differential circuit, characterized in that, in order to improve the measurement accuracy by reducing the drift zero, the working and The reference cells are placed in one common cavity in the heat-conducting block along its axis, and a heat shield is installed around the heat-conducting block. Moreover, the heat shield and temperature difference meters are in thermal contact with the heat-conducting unit on the annular surface in the center, the days of its part.

The device works in the following way.

Capsule 4 with the test substance is blotted into cell 3, and capsule 7 with an inertant substance into cell 6 and closed the cell with lids 5 and 8. The heating (or cooling) of the entire device is turned on. The heat shield II focuses the heat flux on the annular surface in the middle part heat conduction unit and thus converts axial heat fluxes into radial heat. From the middle part of heat conduction unit 1, heat is evenly distributed to both sides along its surface.

The heat flux to heat (or meters 9 and 10 times the temperature. Between the heat-conducting unit 1 and each of the cells 3 and b, there is a temperature difference, n 1 leading emf in meters, emf through the differential circuit enters the recording device.

Formula

e n n

A device for differential thermal analysis, comprising a heat-conducting unit, a working and reference cell and temperature difference meters between the unit and the cells, connected in a differential circuit, characterized in that, in order to improve the measurement accuracy by reducing the drift zero, the working and The reference cells are placed in one common cavity in the heat-conducting block along its axis, and a heat shield is installed around the heat-conducting block. Moreover, the heat shield and temperature difference meters are in thermal contact with the heat-conducting unit on the annular surface in the center, the days of its part.

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Claims (1)

Claim A device for differential thermal analysis containing a heat-conducting block, a working and reference cell, and temperature difference meters between the block and the cells, included in a differential circuit, characterized in that, in order to increase the accuracy of measurements by reducing zero drift, the working and reference cells are placed in one common cavity in the heat-conducting block along its axis, a heat shield is installed around the heat-conducting block, and the heat shield and temperature difference meters are in thermal control kTe with heat conducting unit by the annular surface in the middle portion thereof.