Air change measurements. Maling af luftskifte.

Considers that air change measurement by means of tracer gas is the best way of measuring natural air infiltration in buildings. In some cases the method can be useful for measuring the ventilating air rate in mechanical systems asno interference with the system is required by the method. Deals with the theory of the method, the handling and measurement of different gases, cost of gas and instruments. Concludes by saying that only very simple instrumentation is required for most of the measurements with satisfactory accuracy.