Method of determining thermal conductivity of heat-shielding coatings of highly thermally conductive materials

FIELD: heating.

SUBSTANCE: method is implemented by two thermal effects on two-layer plate with the subsequent cooling, measurement of temperature difference and heat flux. The sample is set with the surface of coating on the heat receiver and the heater. The temperature difference is measured at the points on the opposite surface of the plate, one of which is located on the boundary closest to the heater. Additionally the temperature difference is measured between this point and the environment. The integration starting time is set at the first cooling, and the termination is determined during the second cooling, upon reaching the same temperature difference that at the start. The thermal conductivity is determined by the formula.

EFFECT: increase in accuracy and simplification of determining the thermal conductivity.

3 dwg

 

The invention relates to the field of thermophysical properties of thermal barrier coatings highly heat-conductive materials and can be used in thermal instrumentation.

From an existing prior art known method of determination of thermal conductivity, which is to record the temperature increment of the wire in contact with the studied material sample consisting of a substrate of heat-resistant alloy and a coating thickness of 60 to 500 microns, at a known and constant power electric current. thermal conductivity λ of the material tested is determined by the slope of the straightfrom the equation:

where q is a power of the electric current per unit length of the wire probe;

the temperature increment at time τ0to τ;

λ1- the conductivity of the material, clamping the probe to the sample.

(see Krawczun S. N., Tleubayev A. C. method Using a heated wire to measure thermophysical properties of heat-shielding ceramic coatings/factory laboratory. Diagnostics of materials. 1996. No. 6. P. 31-36).

The disadvantage of this method is the low accuracy due to the influence of the following factors: the contact thermal resistance between the probe and �issleduemymi material, commensurate with thermal resistance of the investigated coating layer; thermal properties of the substrate, since the calculation formula of this method is obtained for a homogeneous infinite body; the difference of the actual measurement values and theoretical, accepted upon receipt of formulas.

Closest to the claimed technical solution is a method of determination of thermal conductivity of insulating layer of small thickness, deposited on a metal substrate, which comprises heating a heat-insulating layer constant heat flux q, adiabatically rear face of the substrate, the thickness of the layer and the substrate, the speed of temperature change on the inner surface of the coating layer and determination of thermal conductivity by the formula (see Thermophysical measurements and devices / ed. by E. S. Platunov. Leningrad: Mashinostroenie, 1986. P. 52):

where t1, t2temperature, respectively, on the outer and inner boundaries of the insulating layer;

t2'- the rate of change of temperature at the inner boundary of the insulating layer;

Nsoftwareλon, HRVWithRV- the thickness and volumetric heat capacity of the coating layer and the substrate.

The disadvantage managementscope solution is the low accuracy, due to the following factors: the influence of thermal contact resistance when measuring the temperature of heat reception surface coating, which is comparable with thermal resistance of the investigated coating layer; measuring the rate of change of temperature; the deviation of the actual measurement values from theoretical, accepted upon receipt of the formulas. In addition, it is difficult technically to implement the temperature measurement at the boundary of the coating-substrate interface.

The basis of the invention is to develop a method that provides improved accuracy and simplification of the technical implementation of thermal conductivity measurement.

To solve this problem in the known method of determination of thermal conductivity of thermal barrier coatings highly heat-conductive material comprising thermal effect on the sample, in the form of a two-layer plate consisting of a heat-shielding coating and the substrate of high heat conductivity material, the measurement of the temperature difference at the boundaries of the investigated area of the sample and the heat flux flowing into it, the plate stack of the coated surface to the heat sink and the heater, the length of which is equal to the width of the plate, carry out the cooling of the sample, is applied to repeated exposure to heat and subsequent cooling, the temperature difference measured in point� the substrate surface, one of which is near to the heater and parallel to the boundary of the given surface, measure the temperature difference between that point and the environment, these quantities are integrated over time, and the time it starts asking for first stage cooling, as determined at the end of the second cooling, the moment it reaches the same temperature as that at the beginning of integration, and thermal conductivity of the coating is determined by the formula

where k0, k1are coefficients determined during the calibration;

- the amount of heat delivered to the sample in the interval [τ1,τ2];

0, L - coordinates of the boundaries of the investigated area of the sample;

Δt(0, τ) is the temperature difference between the surface of the plate, on the border of the investigated area, and the environment;

Hon, λsoftwareH, λ - thickness and thermal conductivity of the coating layer and the plate.

In the inventive method the new set of features: set of two-layer sample on the heater and heat sink, temperature measurement on the sample surface allow to increase the temperature difference in comparison with the prototype, where the difference is measured on the coating thickness. It reduces the effect of contact thermal resistance between the sample and heat-sensitive items�ntom. In addition, the claimed location of measurement points for temperature in relation to the main flow of heat reduces the temperature in the contact zone of the heat-sensitive element with the sample, compared to the temperature difference measured at the site boundary [0, Lx] of the sample. This is due to the significant difference warm streams flowing in parallel through the sample and in each of the heat-sensitive elements. For these reasons, increases the accuracy of determination of thermal conductivity. A new feature is the measurement of the temperature difference Δt (0, τ) with respect to the environment and new condition the end of the integration time reduces the accuracy of determination of thermal conductivity: due to the loss of heat from the surface of the sample and running conditions (see below, the condition (2)) defined by theory of the inventive method. Operation time integration of the measured values also reduces the measurement error of thermal conductivity in comparison with the prototype. In addition, the measurement of the temperature difference on the sample surface greatly simplifies the technical implementation of the method in comparison with the prototype, eliminating the need to introduce heat-sensitive element on the boundary of the covering-plate.

To substantiate the adequacy of the formulas stated STRs�both used the following provision of theory of heat conduction: mathematical description of heat transfer in the object of study is represented as the integral form of the heat equation. Getting the formulas of the method is illustrated by drawings, shown in Fig. 1, Fig. 2, Fig. 3. In its derivation does not apply the solution of the boundary value problem of heat conduction. For plate integral form of the x-coordinate two-dimensional (coordinates: x, z) the heat equation has the following form:

where- average amount of heat through the thickness H of the plate, passing through its end surface (x=0); Qz(x, zj, τ) (zj=z1, z2- the distribution of the x-coordinate of the amount of heat passing through the horizontal boundary surface of the plate on a plot of thermal conductivity measurement [0, L],t(H)(x, τ) is the average thickness of the plate temperature as a function of the coordinates x.

Similar view has an integral form to cover. Due to the small thickness of the plate and cover, their high thermal conductivity and the location of the right border of the investigated area near the heat whose temperature is almost constant during the measurement, you can make the following assumptions when accounting for heat losses due to heat transfer to the sample surface, the temperature difference relative to the environment at the right boundary is equal to zero;

where t (0, z2, τ), t (L, z2, τ) - temperature at the boundaries of the investigated area [0, L] the surface of the plate.

Fold integral form for the plate and cover. For simplicity and in view of the smallness of the amount received eliminate component that takes into account the heat transfer face of the sample surface (x=0). The result is:

The left part of (1) determining the average on the interval [0, L] the amount of heat received from the heater and outgoing, due to conductive and convective heat transfer through the bottom and top surface of the sample, can be expressed via the temperature difference Δt (0, z2, τ) with respect to the environment, using an interpolation polynomial of Lagrange:

Where

- average on the interval [0, L] amount of heat, respectively, received in the sample and lose the sample from its bottom and the upper surface due to convective and conductive heat transfer. Here: Q(τ), Qop(τ) is the specific amount of heat received, respectively, in the sample from the heater and the sample surface in support for thermocouple that measures the temperature at the point with coordinate x=0; α - heat transfer coefficient; L is the distance between the points of temperature measurement on the surface layer�NY; lop, hop, λop- the width, thickness and thermal conductivity of the insulating layer of the support; ln- width of the heater; xn- the distance between the temperature measuring point with coordinate (x=0) and the external border of the heater (see Fig. 1).

In the inventive method provides a zero increment double integral over a certain time interval [τ1, τ2]:

This is achieved through the use of two thermal effects, followed by natural cooling of the sample. To improve the accuracy of fulfillment of conditions (2) at time τ1and τ2in the sample it is necessary to ensure the mode of heat transfer is close to regular. Then the equality of the temperatures t(0, z2, τ1)=t(0, z2, τ2) or their differences, relating to the environment, ensures the coincidence of the temperature distributions in these moments of time, and therefore the condition in (2). In this case, the calculation formula for determining thermal conductivity can be represented as coinciding with the stated in the claims.

In this method, the requirement of achieving the regular mode is not hard, because, as studies have shown that the contribution of the accumulation component in equation (1), under these conditions the measurement is of neznaju�them compared to conductive. Therefore, a slight error when the condition (2) does not lead to a significant error of measurement of thermal conductivity.

The invention is illustrated by drawings, which depict:

Fig. 1 - heat flow diagram of a sample for explaining the obtaining formulas of the method of determination of thermal conductivity: q(τ),qTP(τ) is the heat flow from the heater to the sample and from the sample to the heat sink.

Fig. 2 - schematic structure of the measuring cell for the determination of thermal conductivity of the coating

Fig. 3 - layout of a sample with respect to the heater and the heat sink.

An exemplary embodiment of the inventive method shown in the measuring cell shown in Fig. 2. Its main elements are: two-layer sample 1, consisting of a rectangular plate and coating the heat flow meter 2, the heater 3, the heat sink 4, two supports 5, 6 of insulating material, two thermocouples, made in the form pyatachkovyh, and secured to the ends of the supports. The sample is set by the surface coating on the heater and the heat sink, the heater is attached to the surface heat flow meter, and loose junctions of thermocouples attached to the heat sink. At the initial time τ=0 serves impulse heat duration 5...10 s, providing heating the sample to a temperature close to the maximum. After this, the sample cooled�argue until time when the temperature difference Δt (0, τ1) between the hot junction of thermocouple on the first pole and the environment reaches a predetermined value or within a specified time interval, before the onset of the mode close to regular. Then served a second pulse of heat with the same length and, simultaneously, starts the measurement of quantity of heat and the integration of a temperature difference, which continues until time τ2when the equality of the temperature difference Δt(0, τ1)=Δt(0, τ2). The coefficients of the formulas k0, k1pre-determined by the reference single-layer samples.

This method has been theoretical studies by means of simulation on the model of the measuring cell shown in Fig. 2. Adopted the following values and units used in this model: plate - λ=-7 W/(m·K), a=3,5·10-6m2/C; coating - λon=0,75...100 W/(m·K), andon=(1...20)·10-6m2/s; the thickness of two-layer sample h+ Hon=1 mm with the ratio H/Hon=1, H/Hon=4; heater - hn=0,5·10-3m, λn=20 W/(m·K), andn=5·10-6m2/s; heat flux meter and prop - ht=0,1·10-3m, λ=0.15 W/(m·K), a=1,2·10-7m2/C; the contact zone of the sample - λ=0,026 W/(m·K), a=(0,1÷20)·10-6m2/s, hK=5·10-6m, Teplov�e contact resistance R K=l,9·10-4m2·K/W; L=10.5 mm. Coefficients (k0and k1been pre-determined by the results of simulation calibration with seven standard samples: made of alloy VT-6 - λ=7 W/(m·K), H=0,25; 0,5; 1 mm; steel 12X18H10T - λ=14.5 watts/(m·K), H=0,25; 1 mm; mild steel - λ=60 W/(m·K) - H=0,25; 1 mm; molybdenum MCHVP - λ=133 W/(m·K) - H=0.25 mm. Without taking into account the error of measurement of the thickness of the substrate and the coating, in the presence of a given thermal contact resistance, the error in determining thermal conductivity of the coating does not exceed 2%. Installation of the sample opposite to the surface leads to a significant increase in the error of determining thermal conductivity of the coating.

Method of determination of thermal conductivity of thermal barrier coatings highly heat-conductive material comprising thermal effect on the sample, in the form of a two-layer plate consisting of a heat-shielding coating and the substrate of high heat conductivity material, the measurement of the temperature difference at the boundaries of the investigated area of the sample and the heat flow, flowing, characterized in that the plate stack of the coated surface to the heat sink and the heater, the length of which is equal to the width of the plate, carry out the cooling of the sample, is applied to repeated exposure to heat and subsequent cooling, the temperature difference measured in t�ccah the substrate surface, one of which is near to the heater and parallel to the boundary of the given surface, measure the temperature difference between that point and the environment, these quantities are integrated over time, and the time it starts asking for first stage cooling, as determined at the end of the second cooling, the moment it reaches the same temperature as that at the beginning of integration, and thermal conductivity of the coating is determined by the formula:

where k0, k1are coefficients determined during the calibration;
- the amount of heat delivered to the sample in the interval [τ1, τ2];
0, L - coordinates of the boundaries of the investigated area of the sample;
Δt(0, τ) is the temperature difference between the surface of the plate, on the border of the investigated area, relative to the environment; Hon, λon, Η, λ is the thickness and thermal conductivity of the coating layer and the plate.



 

Same patents:

FIELD: heating.

SUBSTANCE: method is implemented by heat action on a specimen with further cooldown, measurement of temperature difference at boundaries of the test section of the specimen and amount of heat supplied to it during a difference integration period. In addition, the second heat action is performed; temperature drops are measured at these boundaries relative to environmental temperature; time of the beginning of integration is set at the stage of the first cooldown, and its end is determined at the second cooldown, at the moment of equality of weighted sums of temperature drops at the specified points of time: Δt(0, τ2)+pΔt(L, τ2)=Δt(0, τ1)+pΔt(L, τ1), where τ1, τ2 - time of the beginning and end of integration, p - weight coefficient. Heat conductivity is determined by the formula.

EFFECT: increasing accuracy of determination of heat conductivity.

2 dwg

FIELD: oil and gas industry.

SUBSTANCE: stopped well is chosen; its flushing is performed, and with that, temperature at the circulation system outlet is recorded. With that, pumping of hot liquid (heat carrier) is performed through annular space, with that, at its inlet the liquid temperature varies as per a periodic law and is recorded, and heat conductivity coefficient λ"п" and coefficients of heat transfer through tubing strings k1 and casing string k2 are calculated as per mathematical formulas.

EFFECT: improving measurement accuracy of an average integral value of heat conductivity of mine rocks as to a well log and determining coefficients of heat transfer through the tubing strings and through the casing string, length of the circulation system of the well.

FIELD: physics.

SUBSTANCE: device for contactless determination of heat diffusivity of solid bodies contains a flat optical heater and a thermal imager connected to a computer, optically opaque mask for formation of spatial heating field. The device also contains the optical lens intended for focusing of thermal radiation of the flat optical heater and optically opaque shutter allowing to open and close the thermal radiation of the flat optical heater in certain moments.

EFFECT: improvement of accuracy of contactless determination of heat diffusivity of solid bodies.

1 dwg

FIELD: measurement equipment.

SUBSTANCE: invention relates to thermal physics and may be used to determine extent of blackness of the surface of composite and thin-film materials. The method is based on application of sample surface heating and registration of radiation temperature from the sample with coating and available value of blackness extent and from the sample without coating. The proposed solution provides for localisation of the measured section area by means of a special screen from noise impact, and also creation of a local heating area, stable by temperature and area from a special source of heat of directed action. Also application of an IR-mark is provided for preliminary identification of thermal field parameters and operation with least losses.

EFFECT: increased validity of material surface blackness extent determination.

11 cl, 4 dwg

FIELD: measurement equipment.

SUBSTANCE: in accordance with the proposed method they record electric signals corresponding to initial temperatures of surfaces of the investigated sample of the material of at least two reference samples with available heat conductivity and temperature conductivity. Surfaces of investigated and reference samples are heated by an optical source of heat, and electric signals are recorded, which correspond to temperatures of heated surfaces of investigated and reference samples along the heating line, and also in parallel to the heating line at the distance from it. Heat conductivity and temperature conductivity of the investigated sample is determined on the basis of difference of output electric signals corresponding to heated and non-heated surfaces of investigated and reference samples.

EFFECT: increased accuracy of determination of heat conductivity, temperature conductivity and volume heat capacity of materials without preliminary processing of material surface for balancing of their optical characteristics.

7 cl, 1 dwg

FIELD: measurement equipment.

SUBSTANCE: invention relates to thermal physics and may be used to determine extent of blackness of the surface of composite and thin-film materials. The device is applicable whole sample surface is heated, and registration of radiation temperature is carried out from the samples with coating and available value of blackness extent and from the samples without coating. The device provides for localisation of the measured section area by means of a special protective screen from noise impact, and also creation of a local heating area, stable by temperature and area from a special source of heat. Also application of an IR-mark is provided for preliminary identification of thermal field parameters and operation with least losses.

EFFECT: increased validity of material surface blackness extent determination.

7 cl, 5 dwg

FIELD: physics.

SUBSTANCE: method includes applying thermal action from an infrared heat source on the entire surface of analysed isotropic object; using a thermal imaging detector to measure radiant temperature at all points of the spatial grid of the probed surface of the analysed isotropic object; placing the thermal imaging detector at a given distance d from the axis of the geometric centre of the analysed object and circular movement of the thermal imaging detector at a constant speed relative to the geometric centre of the object, or immovably placing the thermal imaging detector at a given distance d from the axis of the geometric centre of the analysed object, while rotating at a constant speed the analysed isotropic object and the background relative to the axis of the rotary structure where they are located; forming a set of thermograms of circular scans of the radiant infrared images of the object and the background obtained at different moments in time; applying a differential model using implicit schemes; determining, from the minimum closing error, unknown estimates for each point of spatial distribution of thermophysical properties of the analysed isotropic object.

EFFECT: high accuracy of obtained data.

5 dwg

FIELD: physics.

SUBSTANCE: method of determining set of thermophysical properties of isotropic materials includes applying thermal action from an infrared heat source on the entire surface of the analysed isotropic material; using a thermal imaging detector to measure radiant temperature at all points of the spatial grid of the surface of the analysed isotropic material; continuous uniform heating of the surface of the reference/analysed isotropic material from a movable infrared heat source; wherein with the beginning of movement, radiant temperature is measured on the surface of the reference isotropic material with known thermophysical properties at one point of the spatial grid of the surface of the reference isotropic material, falling on the lens of the thermal imaging detector; radiant temperature is then measured on the surface of the analysed isotropic material at all points of the spatial grid of the surface of the analysed isotropic material while cooling; applying a differential model using implicit schemes; solving an optimisation parametric problem for the analysed isotropic material at each point of spatial resolution according to the image pattern; determining the unknown estimates of thermophysical properties of the analysed isotropic material from the minimum closing error.

EFFECT: high accuracy of obtained data.

7 dwg

FIELD: physics.

SUBSTANCE: method includes applying thermal action from an infrared heat source on the entire visible surface of analysed isotropic material; using a thermal imaging detector to measure radiant temperature at all points of the spatial grid of the surface of the analysed isotropic material; moving the infrared heat source and the thermal imaging detector along the surface of the isotropic analysed and reference material at constant speed on a curved path; wherein with the beginning of movement, radiant temperature is measured at the centre of the surface each reference material with known thermophysical properties; radiant temperature is then measured on the surface of the analysed isotropic material at all points of the spatial grid of the surface of the analysed isotropic material; applying a differential model using implicit schemes; solving an optimisation parametric problem for the analysed isotropic material at each point of spatial resolution according to the image pattern; determining, from the minimum closing error, unknown estimates for each point of spatial distribution of thermophysical properties of the analysed isotropic object.

EFFECT: high accuracy of obtained data.

6 dwg

FIELD: heating.

SUBSTANCE: invention claims a device for heat exchanger operation parameter measurement, including heat-insulated case of steam generator with cover, insulators, electrodes, heat exchanger connected by pipeline with the cover and bottom part of steam generator, expansion vessel, measurement and computation unit connected to electrodes. Additionally the device includes circulation pump with output connected to heat exchanger input and input connected to steam generator output, liquid and gas flow meters installed in input pipelines, heat carrier pressure and temperature gauges installed at heat exchanger input and output and connected functionally to the measurement and computation unit. Heat exchanger output is linked to steam generator input.

EFFECT: increased range of measured values, extended functional capacities of device.

1 dwg

FIELD: building, particularly for investigating or analyzing materials.

SUBSTANCE: method involves performing adiabatic thermal action on surface of outer structure layer with the use of disc heater arranged in plane of test probe surrounded by protective heat-insulation ring; recording time dependence of investigated material surface temperature; arranging heat flow sensor on contact surface of the second probe instead of disc heater; installing two linear heaters at a distance from disc heater of the first probe and two linear heaters at a distance from heat flow sensor of the second probe; arranging thermoelectric batteries at fixed distance from linear heaters along line parallel to line of heaters location; applying single heat impulse from linear heat sources to outer structure layers to determine heat and physical properties thereof; determining time of temperature field relaxation in controlled points; performing action of heat pulses in both probes from linear heat sources; changing heat pulse frequency up to obtain temperature in points spaced the same distances from linear heaters equal to two pre-determined values along with determining frequencies of heat pulses for the first and the second outer layers correspondingly; determining heat and physical properties of outer structure layers with the use of above information and obtained mathematical relations; performing heat action on inner structure layer with the use of disc heater of the first probe to define heat and physical properties of inner layer; recording heat flux value by sensor arranged on contact surface of the second probe; measuring temperature in points located correspondingly under disc heater and on contact surface of heat flux sensor with the use of pre-measured temperatures in above points, pre-measured value of heat flux passing through structure layers and previously obtained values of heat and physical properties of outer structure layers; determining heat and physical properties of inner structure layer on the base of mathematical relations describing temperature drop in each of three layers.

EFFECT: increased accuracy of heat and physical properties determination in multi-layer articles.

2 dwg

FIELD: investigating and analyzing of materials.

SUBSTANCE: method comprises heating the outer surface of the metallic layer with a disk heater and recording time dependence of the surface temperature. The heater is housed in the space of the central probe, which allows the heat flux to be directed normally to the surface of the contact of the probe with the article The ring probe is mounted concentrically to the central probe to keep the heat flux constant. To exclude the heat exchange with the ambient air, each probe is enveloped with one concentric guard ring.

EFFECT: enhanced speed of response.

1 dwg

FIELD: investigating or analyzing materials.

SUBSTANCE: method comprises setting a specimen to be analyzed between two buffer members made of a material with known thermophysical properties and provided with heater and temperature sensors. After the pulse heating of the specimen with a point heater, the signals from the temperature sensors are digitized and sent to the computer which plots dynamic pattern of thermal wave propagation in the material and calculates thermal conductivity and diffusivity of the material depending on direction.

EFFECT: enhanced efficiency of determining.

2 cl, 3 dwg

FIELD: non-destructive control.

SUBSTANCE: small-sized measuring probe is placed onto thermoplastic material blank. Measuring probe has linear heater (heat source) and thermopiles disposed as on line of action the heater and at preset distances symmetrically at both sides of line of the heater. Then single thermal pulse is generated by linear source and time of relaxation τrel of temperature field and minimal frequency of application of thermal pulses Fmin are determined on the line of influence of the source from the relation of Fmin=l/τrel. After the thermal influence from the heat source is performed by increasing frequency of supply of pulses until speed of heating of tested sample gets the preset value (no more than 1°C per minute). After it the thermopiles disposed at both sides of heater are connected in turn to measuring circuit; first the batteries being the closest to line of action of heater are connected. Thermo-physical characteristics of tested thermoplastic material and speed of heating are calculated on the base of data on temperature-time changes in tested points. As the temperature of sample grows the temperatures are fixed at which temperatures the thermo-physical characteristics change abruptly. Received results are subject to averaging in microprocessor to show them subsequently at indicator screen and put them into on-line storage of microprocessor.

EFFECT: improved efficiency and precision of measurement.

4 dwg, 2 tbl

FIELD: nondestructive control.

SUBSTANCE: samples in form of parallelepiped are subject to symmetrical heating and temperature-time changes are measured at fixed points of tested sample. Moment when regular temperature mode occurs in tested sample is determined and thermal conductivity is calculated on the base of received data. Temperature on the surface of parallelepiped is measured in two points - at the rib and in the middle of face. Moment when steady-state thermal mode occurs in tested sample is determined and temperature at the rib and in the middle of face of the parallelepiped is measured at two preset moments of time. After that the factor of thermal conductivity be determined has to be found.

EFFECT: improved precision of measurement.

2 cl, 6 dwg

FIELD: thermal-physical measurement technology.

SUBSTANCE: temperature of surface of the sample and environment temperature are measured at specific points by means of two temperature detectors. Correction factor is found from received results. Then surface of the sample is put under influence of motionless point heat source. Excess temperatures of surface to be heated are measured by two temperature detectors at specific points at preset moment of time. While keeping on heating the sample, the time moment is measured when temperature of temperature detector being located at the longest distance from spot of heating increases by preset value. Coefficients of thermal diffusivity and thermal conductivity are found from measured parameters.

EFFECT: increased precision of measurement; simplified procedure of measurement.

1 dwg, 1 tbl

FIELD: the invention refers to the field of processing steel and alloys.

SUBSTANCE: the arrangement has a basis, a tube, fixed on the basis, a capacity with hardening compound, on which there are a heater, a sensor of thermal flow and instruments of measuring and registration of temperature. In the thermal flow a thermopair soldered joint is fixed. The tube is fixed on the basis with inclination from the vertical no more than 3Ο. Inside the tube a bushing and a piston are placed. The sensor of the thermal flow is fixed with the help of buckets from one side, and on the opposite side is a counterbalance. The wall of the tube has openings in the zone of the piston's movement.

EFFECT: provides simplification of the arrangement's construction and increases accuracy of precision of measuring results.

2 cl, 1 dwg

FIELD: measurement engineering.

SUBSTANCE: linear pulse heat source is placed onto thermo-insulated surface of tested material. After heat pulse is applied, real temperature is measured in relation to its differential meaning before the preset meaning comes. Time-integrated value of temperature is registered for the purpose.

EFFECT: improved precision of measurement.

2 dwg

FIELD: measurement engineering.

SUBSTANCE: device has second unit for measuring extreme values introduced additionally. Second input of first comparator is connected with output of second integrator which has second control input connected with output of heat pulse duration detector, with second control input of first integrator and second control input of memory unit. Output of memory unit is connected with second data input of switch which has second control input connected with output of second unit for measuring extreme values. Input of unit for measuring extreme values is connected with output of amplifier and second input of second comparator.

EFFECT: simplified design; improved precision of measurements; improved reliability and comfort at usage.

2 dwg

FIELD: thermal physics; measurement engineering.

SUBSTANCE: hot probe has case and measuring head provided with heat-insulated substrate. Heater and main thermoelectric pile made of differentially connected thermocouples is placed onto substrate. Ancillary thermocouple and differential thermocouple are disposed in substrate for checking temperature gradients inside substrate. Thermal flux detector is placed heat-insulated substrate for finding heat leakage into the substrate.

EFFECT: improved precision of measurement.

2 cl, 4 dwg

Up!