Abstract
Mass concentration measurements of airborne suspended particulates have been made on the filtering method. On the otherhand, a light scattering method has been adopted in Japan for the routine monitoring. However, this method has a few defects. In the cases where the system of particulates changes or mist exists in the air, the mesured concentrations are effected and for accurate measurements the calibration procedure is required relating the filtering method.
This paper describes on the characteristics of the dust monitor using a piezoelectric microbalance method, and shows its superiority over the light scattering method. The correcting method of mass sensitivity in this instrument, which is very important for practical use, has been developed applying water-soluble rhodamine. The collection efficiency of sample dusts (quartz powder, polystylene latex and lead fume) in this detector and the effects of relative humidity on measured concentrations are verified in this experiment.
It is proposed that the instrument should be equipped with the humidity regulator for practrical measurement corresponding to the governmental environmental standard of suspended particulates.
