CS242498B1 - Apparatus for measuring of a heat conductivity by means of etalons - Google Patents

Abstract

The solution concerns a measuring device thermal conductivity using standards. The essence of the device is arranged in one axis a heating element (provided with a heating element) on the hinged side heating element (2) and on the drawn thermocouple (3) and cooling a body (4) provided on the engaging side with a thermocouple (5) and on a stripped cooler (6) between which the etalon or sample tested (7). Heater (lj and a cooling body (4J, as well as etalon or the test sample (7) is stored in segments (8) the insulation being mutually measured close to the hinged spring pressure (9) attached to the walls of the cabinet (10) measurements. The device can be used for research, production and testing of construction and insulation materials, wherever they are provided thermal conductivity of substances. The device is designed for thermal measurement conductivity of substances by the method in which part heat flow outside the test sample is measured using etalons of known coefficient thermal conductivity and heat flux tested sample is calculated as the difference between developed heat and heat flowing outside tested sample.

Description

The invention relates to an apparatus for determining the thermal conductivity of substances in which a portion of the heat flowing outside the test sample is detected by measuring standards of known thermal conductivity and the heat flowing through the test sample is calculated as the difference between the heat produced and the heat flowing outside the test sample.

So far the! known thermal conductivity measuring devices are designed to employ methods in which conditions are either created so that the heat generated is overflowed by the quantitative test substance or the heat flux through the test substance is calculated. In both cases or combinations thereof, the devices are technically demanding and the measurement preparation and measurement process is reluctant.

The essence of the device for measuring the thermal conductivity by means of standards is that in the axis of the measured heat flow there are arranged a heating element provided on the opposite side with a heating element and an adjacent thermocouple and a cooling body provided on the adjacent side with a thermocouple and a remote heatsink. a standard or test sample is placed, the shape and dimensions of the walls perpendicular to the axis of the arrangement of both the bodies and the standard and of the test sample are identical and the side walls are parallel to the axis of the arrangement.

In order to achieve repeatable measurement conditions, the heater, the standard or test sample and the radiator up to the radiator are housed in insulation segments that are adjacent to each other by the tilt spring clamps attached to the measurement box walls.

The advantage of the device is its simplicity of construction and simplicity, acceleration of the process of preparation and course of measurement, the possibility of automatic recording of measured temperatures and the possibility of automation of the measurement process.

The drawing shows schematically a vertical section of the device and its connection to a power source and a temperature recorder.

In the device according to the drawing, the metal heater 1 in the form of a regular quadrilateral prism is provided with a resistive heater 2 and a thermocouple 3 and a metal cooling element 4 of the same shape is provided with a thermocouple 5 and a heat sink 6.

The standard or test sample 7 is placed between the metal heating element 1 and the cooling element 4, which coincides in the shape and dimensions of the walls perpendicular to the axis of the arrangement. To provide repeatable measurement conditions, the metal heating element 1, the standard or test sample 7 and the cooling element 4 up to the heat sink 6 are embedded in foamed polystyrene insulation segments 8.

The walls of the individual parts of the device and the insulations abut against each other by the pressure of the tilting spring 9 attached to the walls of the measuring box 10. The resistance heating element 2 is connected to a regulated source 11 of stabilized direct current, the energy flow to the device being measured by means of a voltmeter 12 and an ammeter

13th

The temperatures sensed by thermocouples 3 and 5 are recorded on a twin recorder

14. The measurement is terminated when the temperature difference sensed by thermocouples 3 and 5 is stable. For a correct measurement, the temperature sensed by the thermocouple 3 should be the same as for the measurement of a standard with a known thermal conductivity coefficient at a constant temperature difference.

The device according to the invention can be used mainly for operative measurement of thermal conductivity in the research, production and testing of building and thermal insulation materials and wherever the thermal conductivity of substances has to be determined.

Claims (1)

SUBJECT Device for measuring thermal conductivity by means of standards, characterized in that in the axis of the measured heat flow are arranged metal heater (1) arranged on the opposite side with heating element (2) and on adjacent thermocouple (3) and cooling element (4) provided on the adjacent side with a thermocouple (5) and a remote heat sink (6) between which a standard or test sample (7) is placed, the shape and dimensions of the walls perpendicular to the yn axis of the metal heater (1) and cooling body (4) as well as the standard and the test sample (7) are identical and the side walls parallel to the axis of the arrangement and the metal heater (1), the standard or test sample (7) and the cooling body (4) to the cooler 8) Insulations which abut against each other by the tilt spring pressure (9) attached to the walls of the measurement housing (10).