Abstract: A filter element for fluid filtration, in particular for hydraulic fluid, has element components, such as pleated and multi-layer filter material (10) that extends between two end caps (26) and has a fluid-permeable supporting tube (14) forming a hollow cylinder. At least one element component of the filter element is provided at least partially with at least one luminescent material or marker such that the material or marker is excited to a characteristic, detectable wave emission when exposed to a certain exciter wave or wave spectrum.

Abstract: The invention relates to a filter element for fluid filtration, in particular for hydraulic fluid, consisting of element components, such as a preferably pleated and multi-layer filter material (10) that extends between two end caps (26) and at least partially comprises a fluid-permeable supporting tube (14) forming a hollow cylinder, characterized in that at least one element component of the filter element is provided at least partially with at least one luminescent material or another marker in such a manner that said material or marker is excited to a characteristic, detectable wave emission when exposed to a certain exciter wave or wave spectrum.

Abstract: A filter has a filter medium (10) during operation clears fluid, particularly in the form of hydraulic fluid. The filter medium (10) is made of a material such that the potential difference to the fluid to be cleaned is low. The parts of the filter medium (10) have different potentials with respect to each other and/or the fluid to be cleaned such that they cancel each other at least partially, specific dissipation is aspired, or a return of electric charge to the associated filter medium (10) is provided, using a charge equalization situation.

Abstract: A filter has a filter medium (10) during operation clears fluid, particularly in the form of hydraulic fluid. The filter medium (10) is made of a material such that the potential difference to the fluid to be cleaned is low. The parts of the filter medium (10) have different potentials with respect to each other and/or the fluid to be cleaned such that they cancel each other at least partially, specific dissipation is aspired, or a return of electric charge to the associated filter medium (10) is provided, using a charge equalization situation.

Abstract: A filter has a filter medium (10) during operation clears fluid, particularly in the form of hydraulic fluid. The filter medium (10) is made of a material such that the potential difference to the fluid to be cleaned is low. The parts of the filter medium (10) have different potentials with respect to each other and/or the fluid to be cleaned such that they cancel each other at least partially, specific dissipation is aspired, or a return of electric charge to the associated filter medium (10) is provided, using a charge equalization situation.

Abstract: The invention relates to a filter, comprising a filter medium (10), which during operation is used to clean fluid, particularly in the form of hydraulic fluid, wherein the filter medium (10) is made of a material the potential difference to the fluid to be cleaned is low. The invention further relates to filter solutions, wherein parts of the filter medium (10) have different potentials with respect to each other and/or the fluid to be cleaned such that they cancel each other at least partially, or wherein specific dissipation is aspired, or wherein a return of electric charge to the associated filter medium (10) is provided, using a charge equalization situation.