Flow metering chamber for a gas flow meter having transducer mounting holes and fairing mounted in the gas inlet

A gas flow metering gas chamber, comprising:

• a cavity with a gas inlet arranged at one end thereof and a gas outlet arranged at the other end thereof;
• a first ultrasonic transducer mounting hole being provided at the gas inlet, a second ultrasonic transducer mounting hole being provided at a side wall of the gas outlet, a signal emitting direction of a first ultrasonic transducer installed in the first ultrasonic transducer mounting hole being angled to a direction of the gas flow through the cavity, and a signal emitting direction of a second ultrasonic transducer installed in the second ultrasonic transducer mounting hole intersecting with the direction of the gas flow through the cavity, and a reflection device being provided at the gas outlet, an angle being formed between a reflection surface of the reflection device and the direction of the gas flow, and the reflection surface of the reflection device facing the signal emitting direction of the second ultrasonic transducer installed in the second ultrasonic transducer mounting hole, so that the signals emitted by the first ultrasonic transducer and the signals emitted by the second ultrasonic transducer form a reflection passage through the reflection surface of the reflection device;
• and
• a fairing mounted in the gas inlet, the fairing comprising a mounting portion, a connecting portion and a plurality of mounting projections connected between the mounting portion and the connecting portion, the mounting portion and the connecting portion both having ring configurations, outer diameters of the mounting portion and the connecting portion being less than an inner diameter of the gas inlet, gas intake holes being formed between an inner surface of the gas inlet and outer surfaces of the mounting portion and the connecting portion, the mounting portion and the connecting portion being spaced from each other to thereby form a gas flow channel therebetween, a gas guide hole being defined in the connecting portion, gas diffusely flowing in the gas intake holes of the fairing from front and rear ends of the fairing, and then flowing into the gas flow channel and the gas guide hole in turn and exiting the gas outlet, the ultrasonic signal emitted by any one of the ultrasonic transducers is absorbed by the other ultrasonic transducer after being reflected by the reflection surface of the reflection device.