tested accurately and quickly by the instrument, which until recently was thought to be capable of measuring the thermal conductivity of only such materials as blotting paper, wallboard, glass and all types of insulating materials, John T. Gossett, president, said. Textile manufacturers, he explained, are thus enabled to compare the warmth-retention qualities of various fabrics and to maintain specific standards before distribution to the garment industries.
According to Gossett, a layer of the material being tested is brought in contact with the measuring device which is filled with boiling water and kept at a constant temperature by an immersion heater. The material is then placed on a receiving block of metal of known heat capacity. The temperature changes in the receiver, as affected by the heat being conducted through the material, are measured by means of a thermocouple and the rate at which the receiver increases its temperature determines the insulating value of the fabric.
Well-insulated materials will cause the receiver block to warm up more slowly than those which are poorly insulated, Gossett explained. He also pointed out that the device is useful for measuring the lack of thermal conductivity, providing textile manufacturers with a positive means of determining the most comfortable fabrics for summer as well as winter.
The instrument, he said, is simple to operate and non-destructive to the material being tested.
Department stores are also reported to be interested in the apparatus. At the present time, Gossett said, Marshal Field & Company is employing the instrument in its Chicago testing laboratory for comparing the heat conductivity of synthetic fabrics with those made of wool.