Hot-film air mass meter having frequency-modulated signal detection

US7861586B2 · kind B2 · utility

Assignee

• Robert Bosch GmbH · DE

Inventors

• Bernard Opitz · Leonberg, DE
• Ulrich Wagner · Bernburg, DE
• Axel Franke · Ditzingen, DE
• Carsten Raudzis · Neuffen, DE

Key dates

• Filing date: Jun 13, 2006
• Grant date: Jan 4, 2011
• Expiry date: Jun 13, 2026

Classification

• Technology area (CPC G): Physics
• CPC primary: G01F1/692
• WIPO field: Measurement
• WIPO sector: Instruments

Abstract

A method for measuring an air mass flow flowing in a main flow direction, and a hot-film air mass meter by which the method is able to be realized. The method and the hot-film air mass meter are especially suitable for use in the induction tract of an internal combustion engine. The hot-film air mass meter includes a sensor chip having a chip surface across which an air mass flow is able to flow. The chip surface in turn has a measuring surface, the measuring surface including a central hot-film air mass meter circuit having at least one central heating element and at least two temperature sensors. The method is implemented so that the at least one central heating element is periodically heated using a frequency ω. With the aid of at least two temperature sensors, at least two measuring signals are detected. The measuring signals and/or at least one differential signal of the at least two measuring signals are modulated using the frequency ω.