SU513304A1 - Device for determining the heat capacity of materials - Google Patents

Description

shells 2, 3, in which the meta / ishical sample 4 is placed, the internal source

Nick. heating 5 sample, heat source, 6 sample with low thermal conductivity, sensor of temperature difference 7 of sample and first heat insulating sheath, amplifier signal of temperature difference 8 of sample and first heat insulating coating I, heating power regulator 9 j of the first heat insulating shell with blo-1 power supply, sensor of temperature difference 10 of the sample and the second heat insulating sheath, amplifier signal of the temperature difference 11 of the sample and the second heat insulating sheath, regulator of heating power 12 of the second heat insulating sheath, Precision setting unit of program 13, amplifier of difference of signals 14 from setting device and sensor of sample temperature, controller of program heating of sample 15, automatic search and output unit for operating mode 16, stabilized source of heating of sample 17, switching unit 18 | heating in modes with constant heating rate and with constant calibrated heater power, a recorder 19 of the recording unit of the temperature dependence of the true heat capacity, a signal forming unit of the correction 20 for the heat capacity of calorimeter parts connected to a summing unit 21, a signal generating unit of the reverse heating rate 22 , sample temperature thermocouples 23, 24 and power control sensor 25.

The device works as follows:

The algebraically summed signal of the setpoint generator of sample 13 and the thermocouple of sample 24 is fed through a signal amplifier 14 to the controller 15 of the heating pattern of the sample. Using a software heating regulator of the shape 15 and an automatic search and exit to mode 16, the sample is heated by a stabilized power source 17 through a power control sensor 25 consumed to heat the sample. In this case, quasi-diabatic conditions of the sample are automatically created due to signals from the sensors of the difference in temperature of the sample — and the first and second heat-insulating shells at the output of the corresponding thermostats 9 and 12.

When performing the heating mode of the sample, given behind the sensor 13, with an increase in the temperature of the sample changes -

Etsu heater power. With an atom, the power control sensor 25 forms a signal proportional to (subject to quasi-adiabatic conditions) the heat-i capacity of the material. The recorder 19 records the true heat capacity of the material with good thermal conductivity depending on the temperature. Simultaneously b, by varying the temperature of the sample, block 20 generates a correction signal for the heat capacity of the calorimeter parts. During the measurement, the correction signal is algebraically; summed with the measured value in the i summation block 21. |

When the heating mode is performed at a constant calibrated power (in the case of using materials with a low thermal conductivity when the sample is heated at a constant speed is difficult), it serves

 power meter 25, fixed at a certain signal level. The sample is heated by an internal heater 5, which is connected to the software for heating the sample using a switching unit 18.

To improve the uniformity of heating of the sample, the heater is pressed into the sample during its manufacture. To increase -: the accuracy of the thermocouple reading is also j

o pressed into the sample.

When the sample temperature rises, the signal from the thermocouple is fed to the forming unit 22, where a reverse heating rate signal is produced, proportional to

ny (under the conditions of qualification, conditions) of the true heat capacity of the material, ala. The heat correction signal j of calorimeter parts block 20 modulates to the scale of the inverse nag speed, aj

heat capacity is defined as the result of the algebraic summation of the inverse heating rate and the correction signal in block 1 summation.

Thus, the self-recording register registers the temperature dependence of the true heat capacity.

The access to the computer is provided at the registering complex of the device.

Thus, the device makes it possible to determine the temperature1: th dependence of the true heat capacity as materials with good thermal conductivity, Hanpjb-tep m & tallic samples and materials with low thermal conductivity, for example. metal oxides, refractories, etc.;

In the case of a warm measurement: the bones of the metal samples, the installation operates according to the first mode, that is, the sample is heated at a constant rate. what is provided by the psi. tzammno regulator

jTO Haipeea of J.S.T.S.Also, if the sample is in quasiabatic conditions, the final heat capacity nponoj 1sonal power consumed for the heating of the sample, i.e., the power measurement sensor 25 produces a signal, nponoi rational heat capacity of the material,

At the same time, when determining the heat capacity of a low heat conduction coefficient, such as metal oxides, when it is difficult to maintain a constant heating rate i, the device operates in the second mode — at a constant {heating power. In this case, in the case of 1:; observational quasiadiabatic conditions, the heat capacity is proportional to the inverse velocity of heating. The signal for the reverse heating rate is formed in block 22. To improve the accuracy of the results obtained when the device is operated in the olfactory modes, corrections are made for the heat capacity of the calorimeter parts. Following this, a perfect device for determining the heat capacity makes it possible to expand the capabilities of determining the rate & num- ber of the net heat capacity of materials with high and low thermal conductivity coefficient, increasing 5313304

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I A device for determining the heat content of materials containing a calorimeter, a system for maintaining quaiadiabatic conditions with a heat-protective shell, a measuring circuit, a Tregulation and recording, characterized in that, in order to improve accuracy, it contains a second heat-insulating shell, and an additional IgG is added to the measurement circuit. difference sensor | The equipment includes a second heat source of the iolating shell and a programmable heating sample, including; The first program shutter and the automatic search and exit to the operating mode, depending on the heat capacity of the sample, and the recording circuit, the signal generation unit, the heating rate and the signal generation unit. a correction for the heat capacity of the calorimeter parts, connected to the summing unit;

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