| 摘要 |
Apparatus 10 for analysing the concentration of a test gas in a gas sample by analysing the acoustic signal generated by the test gas when subject to a microwave test signal 16. The apparatus 10 includes a microwave source 14 that emits a microwave signal 16 which is modulated by a modulator 18 and emitted in a resonant cavity 24. The modulated test signal 22 is emitted through the gas sample contained within the gas chamber 12. The test gas generates an acoustic signal at specific microwave frequencies which is measured by an acoustic transducer 28. The acoustic transducer 28 generates an output signal having properties directly related to the concentration of the test gas in the gas chamber 12. The output signal from the acoustic transducer 28 is processed to determine the concentration of the test gas in the gas chamber 12. |
