Exhaust gas sensor

US6071476A · kind A · utility

Assignees

• Motorola, Inc. · US
• Engelhard Corporation · US

Inventors

• Daniel A. Young · Gurnee, US
• Jeffrey D. Naber · Dearborn, US
• Neil J. Adams · Novi, US
• Edward N. Balko · Wilmington, US
• Patrick W. Blosser · Windsor, US
• Linda Hratko · Colonia, US
• Gerald Stephen Koermer · Berkeley Heights, US
• Jie Xue · Beijing, CN
• Adam Moya · Peralta, US
• Chowdary R. Koripella · Albuquerque, US

Key dates

• Filing date: Nov 14, 1997
• Grant date: Jun 6, 2000
• Expiry date: Nov 14, 2017

Classification

• Technology area (CPC G): Physics
• CPC primary: G01N27/16
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A differential calorimetric gas sensor (10) which includes a sensing element (12) having a catalytic layer (14) disposed on a multi-layered substrate (26). Catalytic layer (14) includes an active catalyst region (14a) which oxidizes total combustibles within an exhaust gas stream and a reference catalyst region (14b) which oxidizes selective combustibles within the exhaust gas stream. An electrochemical oxygen source (18) is disposed on an opposite side of multi-layer substrate (26) from sensing element (12). An oxygen sensor cell (170) may be incorporated into electrochemical oxygen source (18). The multi-layered substrate (26) includes a plurality of overlaying insulating layers in which an intermediate layer (60) and a bottom layer (64) support primary heaters (58, 62), and in which another intermediate layer (52) supports compensation heaters (50a, 50b). The primary heaters (58, 62) function to maintain sensor (10) at a substantially constant temperature, while the compensation heaters (50a, 50b) function to restore temperature deviations determined by temperature-sensitive elements (46a, 46b) located on an inner layer (48) overlaying the compensation heaters (50a, 50b) resulti…