GB654534A - Apparatus for measuring the heat-insulating capacity of textile fabrics and the like - Google Patents

Abstract

654,534. Determining heat - coefficients. GIANDOMENICI, U. July 22, 1948, No. 19659. Convention date, May 30, 1942. [Class 97 (iii)] In order to measure the heat insulating capacity of textile fabrics or any other sheet material, a chamber 2, completely enclosed on all sides, is formed of the material on a framework 1, and contains adjustable sources of heat, e.g. electrical resistances 3 and the bulb of a thermometer 4. The heat supplied by the sources 3 is adjusted until the temperature inside the chamber remains constant and the heat-insulating capacity of the fabric is then calculated from the amount of energy consumed in maintaining a desired internal temperature constant. The heat supplied to the chamber may be varied to attain the desired constant temperature by means of a resistance 17 in the supply leads to the heaters 3, the energy consumed being proportional to the square of the voltage as indicated by a voltmeter 18 or, by means of a change-over switch 37, the temperature inside the chamber may be maintained constant by means of a thermostat comprising an electric resistance thermometer 26 controlling a relay 28, in the latter case a wattmeter 29 being included in the circuit to measure the power consumed. The bulb of the thermometer 4 inside the chamber is protected from the direct action of the heaters 3 by asbestos screens 9 and the air inside the chamber is circulated by means of a fan 23. The experiment may be conducted under varying external conditions, humidity and temperature of the surrounding atmosphere being variable by a fan 5 and a water spray 6, a hygrometer 21 and thermometer 22 being supplied for external measurements.