Abstract
Video camera calibrations and field experiments have been conducted to measure air change rates using imaging technique. The calibrations for the 8 mm video camera showed that the dark current caused non-linearity at low reflectance. In the field tests, air change rates in the test house were measured by the video camera and the aerosol monitor using smoke candles as tracers. The regression formula as a function of illuminance and camera f-stops was obtained from a total of forty-seven test runs. It was verified that, if the camera could be well adjusted for the experimental conditions using the formura, the video method could measure air change rates with almost the same precision as derived from the decay curves of smoke particle concentrations using the aerosol monitor.
