| 摘要 |
Devices for monitoring the end of service life of a filter cartridge include a demand substance, a sensing element with a detection point located within or adjacent to the demand substance, a reader for the sensing element, and a fluid delivery device. The detection point of the sensing element is correlated to the service life of a filter cartridge. The correlation is effected by correlation of the residence time of the monitoring device to the residence time of a filter cartridge. The residence time of the monitoring device is correlated to the residence time of the filter cartridge by control of the fluid delivery parameters of the fluid delivery device. The fluid delivery parameters include the flow rate, the demand substance mass, the receptacle cross sectional area, the receptacle volume, the receptacle length, and the demand substance packing density of the monitoring device. |
