| 摘要 |
<p>An indicator system (18) provides a visual indication of the cumulative level of an airborne contaminant. An indicator has a transparent sheath (20) with support medium treated with an acid and a pH indicator (22), as the contaminant is adsorbed, the color changes along the medium (24). The indicator system may be used with an adsorptive filter system to predict the life of adsorption bed assemblies. In one embodiment, a sample flow is taken upstream of the adsorption beds and is calibrated with a flow meter and valve. By monitoring the indicator, an accurate prediction of adsorption bed life may be made.</p> |
