Capacitive pressure-measuring cell having at least one temperature sensor and pressure measurement method

US9976923B2 · kind B2 · utility

Assignee

• ENDRESS+HAUSER GMBH+CO.KG · DE

Inventors

• Martin Burgard · Schopfheim, DE
• Drewes Ulfert · Müllheim, DE
• Nils Ponath · Lörrach, DE
• Andreas Rossberg · Bad Säckingen, DE
• Thomas Uehlin · Schopfheim, DE

Key dates

• Filing date: Nov 14, 2014
• Grant date: May 22, 2018
• Expiry date: Jan 26, 2035

Classification

• Technology area (CPC G): Physics
• CPC primary: G01L9/12
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A pressure sensor comprises an operating circuit and a pressure-measuring cell comprising a counter body, a measurement membrane, which is arranged on the counter body and can be deformed by a pressure to be measured, and a capacitive transducer, which has at least one membrane electrode arranged on the measurement membrane and at least one counter-body electrode arranged on the counter body. The capacitance between the membrane electrode and the counter-body electrode depends on a pressure-dependent deformation of the measurement membrane, wherein at least the membrane electrode has a temperature-dependent impedance. The operating circuit is designed to sense at least one capacitance between the at least one counter-body electrode and the at least one membrane electrode and to provide a pressure measurement value on the basis of at least one capacitance and to determine the impedance of the membrane electrode—particularly, the ohmic portion of the impedance of the membrane electrode.