Pressure sensing device with moisture filter

US6675654B2 · kind B2 · utility

Assignee

• ENDRESS+HAUSER GMBH+CO.KG · DE

Inventors

• Frank Hegner · Bad Kötzting, DE
• Andreas Rossberg · Bad Säckingen, DE
• Elke Schmidt · Bad Säckingen, DE
• Ulfert Drewes · Bad Hersfeld, DE
• Michael Kirst · Lörrach, DE
• Bernhard Walter · Oberkirch, DE

Key dates

• Filing date: May 6, 2002
• Grant date: Jan 13, 2004
• Expiry date: May 6, 2022

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B01D39/2093
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

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. The nanoporous material preferably comprises an inorganic material, in particular Al2O3, TiO2 or SiO2. The nanoporous material is preferably hydrophobic and/or can be impregnated with a hydrophobic layer, preferably a silane, in order …