| 摘要 |
PROBLEM TO BE SOLVED: To provide a gas concentration sensor that can accurately and efficiently measure the concentration of a gas. SOLUTION: This gas concentration sensor is provided with a measuring chamber, used for measuring the concentration of a specific gas contained in a gas to be measured, flow-out and flow-in holes through which the gas to be measured is made to flow in and out of a chamber, and a reflection wall which reflects acoustic waves. The sensor is also provided with an acoustic wave transmitter/receiver, having a transmitting-receiving surface which transmits the acoustic waves toward the reflection wall and, at the same time, receives reflected acoustic waves from the wall. The sensor detects the concentration of the specific gas, based on the propagating time of the acoustic waves from the transmission time to the reception time obtained from the transmitter- receiver. This gas concentration sensor is constituted so that, when a prescribed member is put on a horizontal surface while this sensor is being attached to the member, the transmitting-receiving surface is faced down and a recessed section recessed toward the rear surface side of the reflection wall is arranged on the outer periphery of the wall. COPYRIGHT: (C)2003,JPO
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