Device for determining the internal resistance of a linear oxygen probe

US6868713B2 · kind B2 · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventor

• Stephan Bolz · Pfatter, DE

Key dates

• Filing date: Jul 9, 2003
• Grant date: Mar 22, 2005
• Expiry date: Aug 5, 2023

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N27/4067
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

The device comprises a voltage divider (Rv1, Rv2) to whose two terminals the oscillator signal with a phase position that is mutually opposed is supplied until, in the instance of a switched-on probe heating, the voltage (VRpvs) that is proportional to the probe internal resistance (Rpvs) falls below a predetermined set value (set), whereby, at this point in time, the output signal of the oscillator (SZ) is supplied to both terminals of the voltage divider (Rv1, Rv2) with the same phase position (area 1) thus effecting an amplitude change-over (amplitude amplification).