| 摘要 |
Openings are provided (4, 5) for inflow and outflow of gas to the measurement volume (3). The electro-acoustic components (1, 2) are connected to an electronic unit (30). The electronic unit generates signals which are monotonous functions of sound speed and sound absorption at one or more frequencies of the gas located in the measurement volume (3). At least one temperature indicator (11) is placed in direct connection with the measurement volume (3) and its signal, after amplification in at least one amplifier (22, 23), is used in the electronic unit for compensating the temperature dependency of the sound speed or sound absorption. The distance between the electro-acoustic components corresponds to half a wavelength or multiples thereof of the acoustic waves, with correction for phase turning occurring in the electro-acoustic components (1, 2). |
