Filter monitoring device and method

摘要

A filter device has a physical monitoring unit (4) determining a flow rate of air after a filter at two measuring points (5), where one point is arranged in a place with high air flow rate and another point is arranged in a place with low air flow rate. A chemical monitoring unit (7) includes a sensor for concentration measurement of a conductive substance. An evaluation electronic evaluates measured values of both monitoring units. An independent claim is also included for monitoring a filter.