Isotropic (Standard)

All-round testing of bulk samples

The Isotropic Measurement Module enables direct and simultaneous testing Thermal Conductivity and Thermal Diffusivity of an isotropic bulk sample, using our Hot Disk® sensors. Thermal Effusivity and Specific Heat Capacity are also extracted from these two parameters. The bulk sample can be solid, liquid, granule, powder, paste, gel, foam, or insulator. Both single-sided and double-sided sample testing are supported, where the former enables rapid QC testing while the latter maximizes measurement accuracy.

The foundational Hot Disk® technique relies on clamping two identical sample pieces with the Hot Disk® sensor in between. During testing the Hot Disk® sensor simultaneously generates a tightly controlled heat pulse and precisely monitors the temperature increase. This transient temperature reading deduced the geometrical average of the in-plane and through-plane Thermal Conductivity and the in-plane Thermal Diffusivity of the probed sample volume. For the highest measurement accuracy, the thermal probing depth is set to be between the radius and the diameter of the Hot Disk® sensor.

Working with the Isotropic Measurement Module is easy and requires only a minimum of settings. Even a sample of unknown material properties can quickly be tested and analyzed. The Isotropic Measurement Module can test samples ranging in thickness from several centimeters to sub-millimeters using our largest and smallest diameter Hot Disk® sensors, respectively.

Hot Disk AB’s co-founder invented and patented this groundbreaking measurement technique in 1989^{1 & 2}. His paper published in Review Scientific Instruments in 1991³ presents the theory behind it. The measurement technique has been a standard since 2008 – ISO standard 22007-2. Hot Disk AB contributed to the development of this standard.

1. S. E. Gustafsson, International Patent WO1989008837.↩︎
2. S. E. Gustafsson, US Patent US5044767A.↩︎
3. S. E. Gustafsson, “Transient plane source techniques for thermal conductivity and thermal diffusivity measurements of solid materials”, Rev. Sci. Instrum. 62, pp. 797-804 (1991).↩︎

 

Thermal Conductivity Range:

Instruments	Range
TPS 3500, TPS 2500 S, TPS 2200, TPS 1000	0.03 to 500 W/m/K
TPS 1500	0.03 to 50 W/m/K
TPS 500 S, TPS 500	0.03 to 100 W/m/K
Hot Disk M1	0.03 to 40 W/m/K