An investigation using the tracer gas method for the measurement of ventilation rate in rooms and air flow rate in ducts.

Reviews tracer gas methods for measuring ventilation rate and discusses the diffusion of gases. Describes four tracer gas methods; rate of decay, equilibrium concentration, transfer index and constant concentration. Discusses the analysis of results. Describes an experimental room and series of measurements of air change rate using two methods a) rate of decay, where a balloon filled with gas was burst as a point source and b) equilibrium concentration where tracer gas was released continuously at a constant rate. Discusses results.< Describes further tests in different rooms using decay rate method. Treats use of tracer gas technique to measure air flow rates in ducts.< Concludes decay method has error of 15% in field conditions.