Abstract: A device for determining and/or monitoring a physical or chemical quantity during a process. The device comprises at least one field appliance which exchanges data with a remote monitoring station by means of a data connection. The inventive device is provided with at least one fuel cell which is electrically connected to the field appliance and at least partially covers the energy demand of the field appliance, and the fuel cell is arranged at a distance from said field appliance.

Abstract: A chamber in the interior of a housing communicates with the environment of the housing by means of a gas esxchange path, wherein a filter element with a hydrophobic and/or hydrophobicized, nanoporous material is placed in the gas exchange path. The chamber serves, e.g. to accomodate electronic circuitry, or it is chamed as a reference pressure chamber of a relative pressure sensor. The relative pressure sensor according to the present invention for capturing a measured pressure with respect to a reference pressure comprises a reference pressure path 23 which extends between a surface which can be exposed to the reference pressure and an opening in a reference pressure chamber 22, a filter element 30 which is arranged in the reference pressure path comprising a hydrophobic or hydrophobicized, nanoporous material. The filter element allows pressure compensation on account of its permeability to N2 and O2, while water molecules are selectively blocked.

Abstract: A chamber in the interior of a housing communicates with the environment of the housing by means of a gas esxchange path, wherein a filter element with a hydrophobic and/or hydrophobicized, nanoporous material is placed in the gas exchange path. The chamber serves, e.g. to accomodate electronic circuitry, or it is chamed as a reference pressure chamber of a relative pressure sensor. The relative pressure sensor according to the present invention for capturing a measured pressure with respect to a reference pressure comprises a reference pressure path 23 which extends between a surface which can be exposed to the reference pressure and an opening in a reference pressure chamber 22, a filter element 30 which is arranged in the reference pressure path comprising a hydrophobic or hydrophobicized, nanoporous material. The filter element allows pressure compensation on account of its permeability to N2 and O2, while water molecules are selectively blocked.