Method for operating hot-film air-mass sensors

US7980126B2 · kind B2 · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Bernhard Opitz · Leonberg, DE
• Uwe Konzelmann · Asperg, DE
• Christoph Gmelin · Stuttgart, DE
• Araceli Pison · Gerlingen, DE

Key dates

• Filing date: Feb 23, 2006
• Grant date: Jul 19, 2011
• Expiry date: Jul 19, 2027

Classification

• Technology area (CPC G): Physics
• CPC primary: G01F1/6986
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A method is provided for operating a hot-film air-mass sensor, which can be used especially for measuring air mass flows in the intake tract of an internal combustion engine. The hot-film air-mass sensor has a sensor chip having a sensor frame and a sensor diaphragm having at least one heating element and at least two temperature sensors, a chip carrier for holding the sensor chip and at least one additional heating element. The sensor chip is able to be heated up using the at least one additional heating element. Immediately after shutting down the internal combustion engine, the at least one heating element of the sensor diaphragm is switched off, or is switched to a lower heating power. Furthermore, the at least one additional heating element is switched on for a specified postheating phase. The provided method is particularly suitable for avoiding oil contamination of the hot-film air-mass sensor.