The thermal resistance and thermal conductivity are a measure of how well heat is transported through a material. At Empa, these thermal properties are determined by using a single guarded hot plate constructed according to EN 12667:2001. Homogeneous, plane-parallel material samples can be tested as follows:

• Two-plate configuration
  Suitable for materials where both sides are in contact with another material during use, e.g. mats, air mattresses, and textiles or gloves.

The Kalcos device has two different plates. The large plate has a size of (60 x 60) cm and the small plate (20 x 20) cm.

The samples are positioned horizontally between two plates. The measuring plate (the upper plate) is set to a higher temperature than the cold plate (the lower plate) creating a defined temperature gradient/flux across the sample. To prevent environmental interference, the measuring plate is surrounded by a guard ring, which is set at the same temperature as the measuring plate.

Each test is comprised of five measurements, at three different temperature gradients. The thermal characteristics are determined for two samples using the following parameters:

• The power required to maintain the measurement plate at a constant temperature throughout steady state,
• The temperature difference between the two plates,
• The thickness of the sample, and
• The surface area of the measurement plate.

If you have any queries regarding the suitability, cost or time frames associated with this testing, please do not hesitate to contact us.

EN 511:2006 [en]
Protective gloves against cold / section 5.6 Contact cold

ISO 5085-1:1989 [en]
Textiles - Determination of thermal resistance; Part 1: Low thermal resistance

EN 12667:2001 [en]
Thermal performance of building materials and products – Determination of thermal resistance by means of guarded hot plate and heat flow meter methods. Products of high and medium thermal resistance