| 摘要 |
The invention concerns an air-flow meter, in particular one for measuring the flow of air aspirated by an internal-combustion engine. The flow meter has a main flow channel (11) with a Venturi section (24), and a temperature-dependent measurement resistance (26) located in a bypass channel (12), the bypass channel (12) opening out into the main channel upstream and downstream of the point of minimum flow cross-section (25) of the Venturi section (24). In order to reduce the noise level in the measurement signal (26) due to the measurement resistance, a section (30) of the bypass channel (12) is designed with inlet and outlet openings (34, 35), the central region (31) of this part of the channel accommodating the measurement resistance (26). This section (30) of the channel is designed so that the ratio of the flow cross-section of the central region (31) to the minimum cross-section (25) of the Venturi section (24) is from 1:8 to 1:25 and the ratio of the flow-section of the central region (31) to the cross-section of the inlet and outlet openings (34, 35) is from 1:1 to 1:2. |
