Measuring the R-Value of Insulating Fabrics
Sun Frost has developed a simple device the R-Mat for measuring the R-Value of insulating materials. The R-Mat can measure the thermal resistance of materials used in thermal curtains or clothing.
The device consists of a one-foot square plate, which is uniformly heated. The material to be measured is sown into a one-foot square envelope and the heating plate is then placed in the envelope. The envelope should be sown so edge losses are minimized. By measuring the temperature increase of the plate and monitoring the wattage used to heat the plate the R-Value of the material can be easily calculated.