Hydrophobically coated pressure sensor

US6941814B2 · kind B2 · utility

Assignee

• ENDRESS+HAUSER GMBH+CO.KG · DE

Inventors

• Frank Hegner · Bad Kötzting, DE
• Ulfert Drewes · Bad Hersfeld, DE
• Andreas Rossberg · Bad Säckingen, DE
• Elke Schmidt · Bad Säckingen, DE

Key dates

• Filing date: Dec 18, 2002
• Grant date: Sep 13, 2005
• Expiry date: Dec 18, 2022

Classification

• Technology area (CPC G): Physics
• CPC primary: G01L9/0075
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A pressure sensor for measuring a pressure includes a pressure chamber; and a deformation body, which can be exposed to a medium under pressure, and which, additionally, at least partially bounds the pressure chamber and seals such pressure-tightly from the medium; wherein the walls of the sensor chamber have a hydrophobic coating, which was applied by gas and/or vapor phase deposition. The hydrophobic coating preferably includes a silane. Especially suited are silanes having one or more hydrophobic groups R and one or more anchoring groups X. Especially preferred are: R—Si—X3, R1R2—Si—X2, R1R2R3—Si—X. The hydrophobic group R is preferably an alkyl, perfluoroalkyl, phenyl or perflurorophenyl group. The anchoring group X is preferably an —OH (silanol), —X (halide, e.g. —Cl), —OR (ester, e.g. —OCH3), —NH2 (amine), or —SH (Mercaptosilane). Additionally, aliphatic or cyclic silazanes —Si—NH—Si—, e.g. hexamethyldisilazane, can be used. Likewise suitable are compounds of the type Ry—Me—Xz, with Me=e.g. Zr, Ti.