Thermal Resistance Testing Services

Thermal resistance (Km2 /W) is the temperature difference across a unit area of a material of unit thickness when a unit of heat energy flows through it in unit time. It is the reciprocal of thermal conductivity

Thermal Resistance
TPS (ISO 22007-2:2008)


The Hot Disk Transient Plane Source constitutes an industry benchmark Thermal Property test system. The TPS Thermal Conductivity Instrument is designed for analyzing thermal transport properties of solids, liquids, paste, and powders, including various types of geometry and dimensions. The TPS 2500 S and TPS 1500 Thermal Conductivity Systems are the only Transient Plane Source (TPS) Method to meet a testing standard (ISO/DIS 22007-2.2).

TPS 2500 S THERMAL CONDUCTIVITY METER SPECIFICATIONS

MaterialsSolids, Liquids, Powders & Paste
Thermal Conductivity0.005 to 500 W/mK
Thermal Diffusivity0.1 to 100 mm2/s
Specific Heat CapacityUp to 5 MJ/m3K
Measurement Time1 to 1280 seconds
ReproducibilityTypically better than 1%
AccuracyBetter than 5%
Temperature RangeCryogenic to 750°C
Power RequirementsAdjusted to the line voltage in the country of use
Smallest Sample Dimensions0.01mm High, 2mm Diameter (Cylindrical sample)
Largest Sample SizeUnlimited
Sensor Types AvailableKapton insulated with or without cable (from cryogenic temperatures up to 180°C).
Mica insulated without cable (Room Temp. up to 750°C).
Meets ISO StandardISO/DIS 22007-2.2


ASTM C177

Testing is performed using a guarded-hot-plate apparatus. Two identical samples are placed on opposite sides of the main heater. The main heater and guard heaters are kept at the same temperature. Both auxiliary heaters are maintained a lower temperature. The guard heaters minimize the amount of lateral heat transfer from the main heater. Temperatures are monitored at each surface by thermocouples. The heat transferred through the specimens is equal to the power supplied to the main heater. Thermal equilibrium is established when temperature and voltage readings are steady. http://www.astm.org/Standards/C177.htm

ASTM C 518

This a comparative, or secondary, method of measurement since specimens of known thermal transmission properties shall be used to calibrate the apparatus. Properties of the calibration specimens must be traceable to an absolute measurement method. The calibration specimens should be obtained from a recognized national standards laboratory.

The heat flow meter apparatus establishes steady state one-dimensional heat flux through a test specimen between two parallel plates at constant but different temperatures. By appropriate calibration of the heat flux transducer(s) with calibration standards and by measurement of the plate temperatures and plate separation. Fourier's law of heat conduction is used to calculate thermal conductivity, and thermal resistivity or thermal resistance and thermal conductance. http://www.astm.org/Standards/C518.htm

ASTM D5334

This test method presents a procedure for determining the thermal conductivity of soil and soft rock using a transient heat method. This test method is applicable for both undisturbed and remolded soil specimens and soft rock specimens. This test method is suitable only for isotropic aterials. http://www.astm.org/Standards/D5334.htm

ASTM 1530

This test method covers a steady-state technique for the determination of the resistance to thermal transmission (thermal resistance) of materials in thicknesses of less than 25 mm. For homogeneous opaque solid specimens of a representative thickness, thermal conductivity can be determined (see Note 0). This test method is useful for specimens having a thermal resistance in the range from 10 to 400 104 m 2K/W, which can be obtained from materials of thermal conductivity in the approximate range from 0.1 to 30 W/(mK) over the approximate temperature range from 150 to 600 K. It can be used outside these ranges with reduced accuracy for thicker specimens and for thermal conductivity values up to 60 W/(mK). http://www.astm.org/Standards/E1530.htm