Method of determining glass-transition point of tetrazole-based polymer composite materials
SUBSTANCE: disclosed is a method of determining the glass-transition point of tetrazole-based polymer composite materials based, according to which the glass-transition point is determined from the change of slope of a curve of temperature versus the inverse of dielectric constant 1/ε'=f(T).
EFFECT: high accuracy and reliability of determining the glass-transition point of tetrazole-based polymer composite materials.
4 dwg, 1 tbl
The invention relates to the field of innovative technologies and can be applied to improve the efficiency of determining functional parameters of polymer composites, which is the element base for future technical systems and devices.
Composites - volume monolithic artificial combination of diverse shape and properties of two or more components, with clear boundary, using the advantages of each of them and showing new properties, due to boundary processes. For composite materials characterized by the following signs: form and composition of the components determined in advance; the components are present in amounts providing the desired properties of the material; the material is homogeneous in the macro-scale and heterogeneous at the microscale; material there is a clear border between the components and gradientnoi patterns. One of the components of the material is continuous throughout the volume of the matrix component, a discontinuous volume, separated by a matrix, is reinforcing or reinforcing.
The composite differs from the alloy to the fact that in the finished composite individual components retain their properties. Components must interact at the interface of the composite, showing only positive new properties. This result mo is only be obtained in the case if composite materials are successfully combined the properties of the components, i.e. during operation of the composite should be shown only the required properties of the components, and their shortcomings, completely or partially neutralized.
Perfectly justified and purposeful creation of composites with desired properties is only possible with the knowledge of the physico-chemical structure of components, the physical chemistry of the processes at the interface, mechanics of deformation and fracture of heterogeneous and anisotropic phone
If the polymer composite materials (PCM) cooling to a very low temperature at which molecular mobility is missing, and then perform electrical measurements, gradually increasing the temperature, the PCM will then "unfreeze" the different types of molecular motion.
Almost every kind of "unfrozen" thus the molecular movements will leave its imprint on the curves tgδ=f(T), ε'=f(T), ε"=f(T) and so on Each type of molecular motion is usually associated with a certain relaxation process, the cause of which is this type of molecular motion. At very low temperature relaxation times almost all relaxation processes are very high, and for them the condition ωτ>>1. So the AK in the first approximation exp ~(U/RT), with increasing temperature all relaxation times are reduced (sometimes mnogokratko), and when for any relaxation process the condition ωτ=1, the temperature dependence of diabeticheskih losses (for example, tgδ) appears high. Under these same conditions will increase the dielectric constant.
If measurements at a fixed frequency over a very wide temperature range, it is possible to identify all specific to the polymer relaxation processes due to different types of molecular motion, which can be realized in the polymer. The manifestation of each type of molecular motion, which leads to significant changes of the temperature dependence of electrical properties, usually interpreted as the temperature transition. In amorphous polymers the temperature transitions are relaxing in nature. In crystalline polymers to thermal transitions are and thermodynamic phase transitions .
Major thermal transitions in amorphous polymers is shown in Fig.1. Usually the temperature transitions, starting with the most intensive high-temperature transition, denoted by Greek letters α, β, γ, δ. Accordingly relaxation processes occurring during the temperature decrease, usually denoted α, β, γ, δ.
On the main relaxation process, which is the main relaxation area (α - relaxation), associated with the transition from the glassy state in highly elastic (or Vice versa). This temperature change is "unfreezing" segmental mobility microprocessor type and leads to major change in the electrical parameters and the appearance of the most intense peak losses. Molecular mobility in this case is due to large kinetic elements of the main polymer chain. The temperature transition, the corresponding α-relaxation, can be single or multi-blade block.
The physical properties of a polymer in the glassy state is very significantly different from similar properties in the highly elastic state. Conventional boundary between these States is the glass transition temperature Tg- the most important characteristic of amorphous polymers, introduced by Aberration. Below the glass transition temperature see temperature at which the viscosity of the polymer is not less than 1012PA·C. It is also interpreted as the temperature below which the "frozen" motion segments of the polymer molecules .
There are many methods of experimental determination of glass transition temperature. There is a method of determining the glass transition temperature by acoustic emission method, which bases the n measuring pulse rate (activity) of pulses, occur in the material . In the course of the experiment is the simultaneous measurement of temperature and activity of acoustic emission (AE) during cooling of the material, the glass transition temperature is determined by a sharp increase in AE activity. The disadvantage of this method is the need for simultaneous measurement values of the two parameters.
There is a method of determining the glass transition temperature of the polymer, including photoresistive films by building a "thermo-optical curve taken in a wide range of temperatures (100-180°C) . As a temperature-dependent parameter selects the refractive index of the film, which is controlled at a wavelength of 546.1 nm. The disadvantages of this method are the need to conduct a series of experiments on the same system and the narrow temperature interval.
The use of dielectric method sometimes due to the difficulties in measuring the temperature and frequency dependencies of the dielectric loss at low frequencies. So urgent is the issue of empowerment of the method of dielectric spectroscopy to determine the Tg.
The purpose of the invention is the creation of a new method for determination of glass transition temperature, using as a criterion to estimate the values of Tgtemperature dependence of the reciprocal dielectric permeable the minute 1/ε'.
According to the relaxation model Drude dielectric response of the dielectric permittivity as a function of temperature and frequency is determined by the expression:
where, ω=2πf is the angular frequency, τ(T) is the relaxation time depending on the temperature, ε∞- dielectric constant when f→∞, εs- dielectric constant when f→0. Decomposition of complex dielectric permittivity of its real and imaginary parts we obtain:
To describe the features of the relaxation processes in the transition region of the glass transition, in the work of the authors  introduced an empirical model of the temperature dependence of the time of vitrification:
Approximation of the experimental curves of the temperature dependence of the reciprocal dielectric constant, under views (1)-(3) leads to at least two straight portions, which correspond to stay polymer systems in glassy and highly elastic state (Fig.2). In the transition region, called the glass transition temperature, there is a sharp change in the dielectric constant and the presence of the maximum tangent of the dielectric loss. Therefore, the temperature dependency 1/ε' can be used for op is adelene interval vitrification.
List of figures
Fig.1 is a Diagram of temperature transitions in amorphous polymer.
Fig.2 - Temperature dependence of the reciprocal dielectric constant at a frequency of 2.10-2Hz. The solid line is theoretical calculation according to the model.
Fig.3 - Temperature dependence of the reciprocal dielectric constant for a sample of system No. 1.
Fig.4 - Temperature dependence of the reciprocal dielectric constant for a sample of system No. 2.
Here is an example implementation of the method.
The study of the temperature dependence of the dielectric parameters (components of the complex dielectric permittivity ε' and ε").
Samples for the study were right-on the basis of poly-N-methylallyl-5-vinyltetrazole (MPWT AND, with the use of plasticizers dimethylformamide (DMF) (system No. 1) and dimethylphthalate (DMF) (system No. 2). Modifier for samples No. 2 was KNO3(55%). The curing of the samples was carried out by low-temperature curing agent di-N-oxide-1,3-dinitrile-2,4,6-treatinent (TONE-2).
Measurement of dielectric spectra were carried out on the installation "Concept 41" company NOVOCONTROL Technologies GmbH & Co, which consists of a frequency analyzer impedance measuring cell systems, temperature control systems, automatic data collection the Dewar vessel with the evaporation system and supply of gaseous nitrogen according to the method described in the work, in a wide interval of frequencies (f=10-1-106Hz) and temperatures (T=273-423 K).
The study on the temperature dependence of the reciprocal dielectric constant 1/ε' (1 Hz frequency) detected the existence of two regions - from 273 K to 325 K and 325 K to 393 K for a system of sample No. 1 (Fig.3), from 273 K to 310 K and 310 K to 393 K for a system of sample No. 2 (Fig.4).
The first area is marked by a sharp decrease in 1/ε', for such a significant change of the temperature dependence of the dielectric parameters associated with the main transition temperature of the glassy state in highly elastic (or Vice versa).
The second area corresponds to the area of highly elastic to plastic state. Analysis of the temperature dependence shows that this area is characterized by a gradual decrease in 1/ε' and output it on a stable plateau.
The temperature at which there is a change of character of the temperature dependence of the reciprocal dielectric constant for all investigated systems the same as their glass transition temperature (table.1)
|Polymer||Tgfrom the literature|
|(MPWT-A) (DMF) (TONE-2)||324 K||325 Kthe 6 is|
|(MPWT-A) (DMF) (MeO-TONE)||329 K||330 Kthe 6 is|
|(MPWT-A) (DMF) [KNO3(55%)] (TONE-2)||310 K||310 Kthe 7 is|
|(MPWT-A) (DMF) [KCl(70%)] (TONE-2)||326 K||326 Kthe 8 is|
|(MPWT-A) (DMF) (Dur-TONE)||327 K||-|
Thus, the detected pilot feature can be used as an alternative method of determining 7g new tetrazole-containing polymer systems.
Sources of information
1. Bartenev, M., Zelenev Yu Century Physics and mechanics of polymers. - M.: Higher school. - 1984. - S. 391;
2. Kozlov N. A. Mitrofanov, A. D. C. Polymer physics: Textbook. manual / Vladim. state University; Vladimir, 2001. 345 S.;
3. Patent - 94029964.
4. Patent - 2193186.
5. Vendik, I. B.; Vendik, O. G.; Afanasjev, V. P.; Sokolova, I. M.; Chigirev, D. A.; Castro, R. A.; Jansen, K. M. B. Correlation between Electrical and Mechanical Properties of Polymer Composite / Proceedings of the Electronic Components and Technology Conference (ECTC), 2011 IEEE 61st. Lake Buena Vista, Florida USA. May 31 - June 3, 201. P. 1697-1702. DOI: 10.1109/ECTC.2011.5898740.;
6. Petrakov P. C. study of the relaxation properties of new tetrazole-containing polymer and model compounds based on it // Diss. for obtaining the academic Art. K. so-called Biysk. 2012.;
7. Kalinin, M. A., Petrakov P. C., Lushin E. P., Tereshchenko, I. A., Sapozhnikov So Century. // Theses and reports the IV-th all-Russian scientific-practical conference of students, postgraduates and young scientists. / Alt. state technology. University, BTI. Biysk: Izd-vo Alt. state technology. University, 2010. S. 59.;
8. Nasonov, A. D. Effect of chemical structure of modifiers on the viscoelastic properties of new tetrazole-containing polymer / A. D. Nasonov, E. A. Paznikov, P. C. of Petrakov, M. A. Kalinin, P. D. Dove // Electronic journal. Scientific notes. - S. 11-14. http://www.scientific-notes.ru/index.php?page=6&new=15.
The method of determining the glass transition temperature of polymer composite materials on the basis of tetrazole, characterized in that the glass transition temperature is determined by the change in the slope of the graph of the temperature dependence of the reciprocal of the real part of the complex dielectric constant 1/ε'=f(T).
SUBSTANCE: invention refers to medicine, namely to oncology, and can be used for recognising synchronous multifocal colorectal carcinoma. Substance of the invention consists in measuring preoperative blood follicle-stimulating hormone both in male and female patients suffering from colorectal carcinoma. If its concentration falls within the range of 26.01 to 60.91 IU/l in the females and of 2.71 to 5.67 IU/ml in the males, a single tumour is diagnosed in the patients, and if the hormone concentration is from 2.70 to 5.50 IU/ml in the females and from 12.88 to 52.04 IU/l in the males, the presence of synchronous colorectal new growths are stated. The method can be implemented at the preoperative stage; it is easily reproducible in the oncology hospital environment.
EFFECT: stating the presence of synchronous multifocal colorectal carcinoma.
SUBSTANCE: invention relates to field of producing carbon-carbon composite materials for various purposes, and is intended for comparative characteristic of impregnation of carbon fibre (CF) braids with melts of pitches, and can be used in improvement of technologies of producing carbon-carbon composite materials, possessing various properties, by modification or replacement of pitch binder and/or carbon fibre, for instance, in research laboratories, in particular, in carrying out laboratory work. To determine degree of impregnation of carbon fibre braids with pitches, carbon fibre braid is placed into glass tube in such a way that the end of braid protrudes from glass tube, and carbon fibres in braid are oriented along glass tube axis, with braid thickness being selected in such a way that it tightly fits glass tube, protruding end of carbon fibre braid is brought in contact with melted pitch and keep in such position, after which carbon fibre braid is extracted from tube and height of impregnation of carbon fibre braid with pitch is determined.
EFFECT: simplification and acceleration of determination are achieved.
1 ex, 3 dwg
SUBSTANCE: method involves cutting a sample for analysis and analysing its chemical composition, from which the rubber brand is determined. The sample is cut such that it has pre-decomposition zones. Chemical composition is analysed from a fracture in the sample by X-ray spectral technique on a scanning electron microscope with an energy-dispersive spectrometer. The obtained data on chemical composition of the sample are compared with chemical composition of a known rubber brand or a rubber brand used as a reference.
EFFECT: high accuracy and objectivity of determining a rubber brand.
3 ex, 1 tbl, 2 dwg
SUBSTANCE: method involves titration of a suspension with a solvent which is soluble in water and dissolves the suspended resin-like substance until reducing light scattering, which is determined either visually or using optical devices which enable to measure the amount of light passing through the liquid.
EFFECT: rapid estimation of the amount of resin-like substance suspended in water.
SUBSTANCE: apparatus has a clamp mechanism for holding material, an indenter for loading with possibility of measuring its displacement and recording information into a processor. A sensor is built into the indenter, said sensor being sensitive to the spectrum of acoustic emission generated by a sample upon change of deformation characteristics thereof. The clamp mechanism is in form of two coaxially placed cups with built-in heating elements with a controlled temperature range and a sensor for said temperature.
EFFECT: broader technological capabilities of the apparatus and high measurement accuracy.
SUBSTANCE: before testing in a heat chamber, samples of polymer materials are activated with UV radiation in the 248-365 nm wavelength range for 3-30 minutes with radiation power density of 1-15 mW/cm2. Analysis of volatile organic compounds is carried out while comparing the obtained chromatograms of gas samples collected from the heat chamber when testing samples of polymer materials with selected additives based on nanostructured bentonite powder and nanostructured bentonite powder intercalated with metal ions - magnesium (Mg2+ ), scandium (Sc3+), chromium (Cr3+), manganese (Mn2+), iron (Fe2+), cobalt (Co2+), nickel (Ni2+), copper (Cu2+), zinc (Zn2+), tin (Sn2+), cerium (Ce3+) or a mixture of bentonite powders intercalated with ions of said metals. The results of comparing chromatograms of gas samples are used to evaluate the effect of nanocomponents on the predicted sanitary-chemical properties of the designed polymer materials.
EFFECT: realisation of the present invention widens technological capabilities and increases reliability of results of evaluating the effect of modifying mineral nanocomponents on predicted sanitary-chemical properties based on release of volatile organic compounds from the designed polymer materials.
8 cl, 7 ex, 2 tbl, 4 dwg
FIELD: textile, paper.
SUBSTANCE: at the first stage the organoleptic analysis of tested samples is carried out. At the second stage the microscopic analysis of the material structure is carried out. At the third stage the chemical analysis of the tested samples is carried out by means of their treatment with an organic dissolvent selected from the group: butyl ether of acetic acid, dimethylketone, dimethylformamide, tetrahydrofuran, furfural, cyclohexanol at the ratio of sample-dissolvent equal to 1:(10-15) at the boiling temperature of the selected dissolvent for 20-30 minutes. If a sample has dissolved fully, the conclusion is made that is pertains to leather-like materials, and if a sample has not dissolved, it is identified as leather.
EFFECT: accurate and reliable recognition of leather from leather-like materials.
2 cl, 3 ex
SUBSTANCE: method involves pre-activation of surfaces of an article and a film. The article then pressed to the surface of the film made from non-light-stabilised polyethylene and then exposed to UV radiation until a brittle layer forms.
EFFECT: formation of a coating on an article, which is adhesively bonded to the surface of the article.
SUBSTANCE: method involves providing a specimen, irradiating the specimen with a predetermined spectrum of electromagnetic radiation, recording the interaction between the specimen and the electromagnetic radiation in a data packet and determining at least one characteristic parameter in the recorded data packet. Radiation intensity values assigned to different areas of the surface of the specimen, where said radiation interacts with said surface areas, are recorded in the data packet. The determined characteristic parameter describes air content in the specimen and/or resin content in the specimen. The assigned intensity values coinciding with a predetermined intensity range are added together to determine the air content and/or the resin content in the specimen. Analysis can also be performed to determine resin distribution and/or air distribution in the sample and homogeneity of distribution of assigned intensity values coinciding with the predetermined intensity range with respect to different areas of the surface.
EFFECT: possibility of analysing specific characteristic parameters.
6 cl, 8 dwg
FIELD: textile, paper.
SUBSTANCE: when boiling collagen, linear dimensions of leather tissue are measured before and after collagen boiling. The structure-to-structure distance is determined using difference of the sample thickness after boiling and the rated thickness of the sample before boiling, which is produced as a product of the sample thickness before boiling and a coefficient of layers number defined as a quotient from division of a lengthy sample length into the length of the sample after boiling. Invention makes it possible to realise the specified method objective.
EFFECT: method improvement.
4 ex, 3 tbl
FIELD: measurement equipment.
SUBSTANCE: method is based on experimental determination of temperature of avalanching disintegration of cooling liquid on a hot surface, in static conditions, without liquid flow.
EFFECT: simplification of rejecting different lots of cooling liquid, decreasing amount of substance in investigated sample and consequently improved safety for personnel engaged in tests.
FIELD: measurement equipment.
SUBSTANCE: method for examination of thermophysical properties of liquids is proposed. It implies that a metal probe of vibration viscosity metre equipped by a temperature sensor is placed to a metal cell with a liquid sample equipped by a temperature sensor. The probe is set to harmonic vibration mode, the cell temperature is changed by a controlled cooling-heating device. Temperature, amplitude, phase and vibration frequency of the probe are measured and density, viscosity and thermal diffusivity of the liquid is determined depending on its temperature. Measurements are made to define dependency on the temperature of the liquid's optical transmission near the probe for the moments when the probe passes its equilibrium position. Device for the method implementation comprises a cell, a controlled cooling-heating device, spherical metal probe of vibration viscosity metre placed inside the cell. The probe and the cell are equipped by temperature sensors. The cell is also equipped with a fibre-optical sensor of liquid optical transmission which is set next to the probe.
EFFECT: improved accuracy of measurement.
2 cl, 2 dwg
FIELD: measurement equipment.
SUBSTANCE: substance consists in availability of a measurement device and a thermoresistive sensor of phase condition in a device for determination of phase condition of a gas and liquid flow, and the sensor comprises a printed circuit board arranged along the axis of flow movement and rigidly fixed by one short side with a sensitive element installed on it and made in the form of a substrate, on which a film resistor of the "point" design (a thermistor) is installed. The sensitive element is installed in the reference point along the vertical axis of the pipeline cross section and is connected with the measurement device, which comprises a metering circuit and a microcontroller with program control and is designed to measure variation of thermistor resistance, connected with variation of the phase condition of the medium in horizontal layers of the gas and liquid flow, and signal processing. At the same time the sensitive element of the sensor by one short side of the substrate is fixed on the edge of the short non-fixed side of the printed circuit board. The film resistor (thermistor) placed on the substrate is displaced towards the edge of the free short side of the substrate and is arranged at the distance of not more than 0.5 mm from this edge. Contact sites designed for connection of the substrate to the printed circuit board are arranged opposite to the thermistor at the opposite short side of the substrate.
EFFECT: higher efficiency of a device to determine phase condition of a gas and liquid flow.
SUBSTANCE: method for determining temperature of full polymorphous transformation of heat-resistant two-phase titanium allows of (α+β)-martensitic class is proposed, which involves preliminary preparation of a specimen by means of multistage heat treatment of the latter, which is performed immediately in a differential thermal analysis (DTA) instrument in atmosphere of cleaned argon and its investigation using DTA method. Heating of the alloy specimen to single-phase β-area, supercooling below temperatures of active diffusional decay of β solid solution, short-term exposure and repeated heating to the single-phase area is performed. Fixation of dependence of a DTA signal on temperature and calculation of values of derivative of DTA signal on temperature is performed, and temperature of completion of full polymorphous transformation is determined as per maximum on the curve of the first derivative of DTA signal at repeated high-temperature heatinge.
EFFECT: improving determination accuracy of temperature of full polymorphous transformation in heat-resistant two-phase titanium alloys.
SUBSTANCE: oil sample is heated with one-time temperature control, the sample is continuously cooled with simultaneous measurement of shear stress. Chilling point is determined from temperature corresponding to the first abrupt increase in shear stress, and bulk freezing point is determined from temperature corresponding to the second abrupt increase in shear stress. The sample is heated to temperature of 60-80°C. Heating and temperature control of the sample is carried out while revolving the viscometer cylinder and the sample is cooled at a rate of 1-2°C per minute.
EFFECT: high information value and reliability of the analysis method.
FIELD: test engineering.
SUBSTANCE: body under study is brought into thermal contact with the reference body in the plane in which the local circular heater is located. At regular intervals of time the difference of values of the temperature between the heater and the point of plane of contact of the body under study and reference body is measured. The tests end up in excess of the specified value by the controlled dynamic parameter. The dependence of the current value of thermal activity on the temperature of the body under study is made. The structural transitions in polymeric materials are determined by the presence of peaks on dependence of the current value of the thermal activity on the temperature of the body under study.
EFFECT: improved method.
SUBSTANCE: method of determining volatility and heat of vaporisation of a mixture of liquid substances from the rate of evaporation from a flat surface involves establishing a correlation relationship between volatility values, calculated using known reference data, for individual liquid substances selected as calibration liquids, and the rate of evaporation thereof, determined based on data from thermogravimetric analysis carried out in isothermic conditions when an equilibrium state is achieved. The rate of evaporation of the analysed mixture is determined and the volatility value is found from the correlation relationship. The heat of vaporisation of the mixture of liquid substances in the analysed temperature range is determined using the relationship between the found volatility values and temperature. The value of the heat of vaporisation is determined from the value of the slope of a linear graph, the abscissa of which is the value of the inverse absolute temperature and the ordinate is the logarithm of the product of the experimentally determined volatility value and the absolute temperature value.
EFFECT: high reliability and objectivity of estimating volatility of not only individual liquids, but also mixtures thereof at different temperatures, broader functional capabilities of the method of determining volatility.
2 cl, 6 dwg
SUBSTANCE: method involves separate temperature control of cylindrical samples which make up a eutectic system, one of which has the analysed composition and the other is homogeneous, for example, consists of a pure substance. The samples are brought into contact at analysis temperature which is higher than the eutectic point, and the position of imaging point of the analysed alloy relative the solidus curve is determined from the state of the liquid layer formed between the samples.
EFFECT: invention enables more accurate plotting of a solidus curve on a phase diagram.
3 dwg, 1 tbl, 1 ex
SUBSTANCE: method of determining thermo-oxidative stability of lubricating materials involves heating the lubricating material in the presence of air and mixing. Oxidised lubricating material is then collected. Oxidation process parameters are then photometered and determined using graphical curves. Two samples of the lubricating material of constant weight are tested separately with and without a catalyst. While heating, the two samples of lubricating material of constant weight are tested successively with and without a catalyst, stirred while periodically varying testing temperature from temperature at the onset of oxidation and maximum temperature. Temperature is the lowered from maximum temperature to temperature at the onset of oxidation over a constant period of time. After each testing temperature, with and without a catalyst, the samples are weighed, the weight of the evaporated sample and evaporation number are then determined as a ratio of the weight of the evaporated sample to the weight of the remaining sample. By photometering, the light flux absorption factor with and without catalyst is determined, the thermo-oxidative stability factor is determined as a sum of light flux absorption factor and evaporation number. Further, the influence coefficient of the catalyst KVK on oxidative processes is determined using the formula KVK=KK/K, where KK and K are thermo-oxidative stability factors of samples of the lubricating material with and without catalyst, respectively. A curve of the influence coefficient of the catalyst on the oxidative processes versus the testing time is then plotted, and thermo-oxidative stability of the lubricating materials is then determined from values of the influence coefficent of the catalyst on the curve. If KVK>1, thermo-oxidative stability is falling, and if KVK<1 thermo-oxidative stability is increasing.
EFFECT: high information content of the method of determining thermo-oxidative stability of oxidation and evaporation processes during periodic variation of the testing temperature.
3 dwg, 1 tbl
SUBSTANCE: proposed method consists in measuring activity of acoustic emission signals emitted by tested specimen in heating. Polymorphic transformation temperature is defined as temperature corresponding to the moment of stepwise decrease in aforesaid activity.
EFFECT: higher accuracy and efficiency.
FIELD: investigating or analyzing materials.
SUBSTANCE: thermograph comprises differential thermocouple and aluminum thermal unit provided with two symmetrically arranged cylindrical holes for crucible with specimen and standard. The crucibles are made of cylinders with caps provided with copper pipes for hot junctions of Chromel-cupel thermocouples. The wires of the thermocouples are housed in the two-channel ceramic rods. The thermoelectric heating of the unit is provided with the use of temperature-sensitive resistor made of nichrome wire. The unit is mounted in the steel sealed housing with a lid and provided with a device for locking it inside the housing during cooling and heating.
EFFECT: simplified design and enhanced accuracy of measuring.