| 摘要 |
A method and an apparatus are disclosed for determining the U-Value of a wall, or of any other construction element having two opposed substantially fiat surfaces. The method comprises: measuring the initial temperature of both wall surfaces at two positions which are substantially opposite each other on either side of the wall, and either, if the two measured temperatures are different modifying the temperature of a first closed volume defining a first predetermined area of wall surface surrounding at least one of said positions by applying energy to neat or to cool the first volume and the first area of wall so that the temperature of the area of wall is substantially uniform and substantially the same as the initial measured temperature on that side of the wall or, if the two measured temperatures are substantially the same, modifying the temperature of a first dosed volume defining a first predetermined area of wall surface surrounding at least one of said positions by applying energy to heat or to cool the first volume and the area of wail so that the temperature of the area of wall is substantially uniform and differs from the measured temperature and using the measured temperatures, the first predetermined area and the heating or cooling energy to determine the. instantaneous U-Value. Also disclosed in a method comprising the use of first and second closed volumes, one on each side of the wall. |
