Filtering apparatus for filtering compressed air

A filter device for the filtration of compressed air comprising:

• a housing, said housing having a principal body and including a principal fluid duct extending having an inlet and an outlet;
• a filter means, said filter means selectively coupled to said housing, said filter means positioned between said inlet and said outlet to filter air from said inlet to said outlet;
• a detection means said detection means producing at least one electrical detect signal for indicating the installation or removal of said filter means;
• an electronic evaluation means, said electronic evaluation means receiving said electrical detect signal;
• a recognition means, said recognition means detecting the degree of clogging of the filter means, said recognition means further including a pressure differential sensor, said pressure differential sensor is responsive to a pressure differential between said inlet and said outlet, and a flow sensor means said flow sensor means detecting a flow rate in the principal fluid duct, wherein said detected pressure differential values and detected flow rate value are evaluated by said electronic evaluating means to yield a condition value relevant for the degree of clogging of the filter means;
• and
• said electronic evaluating means having a preset limit value, wherein said preset limit value is compared to said condition value to indicate a degree of clogging of said filter.