| 摘要 |
<p>The measuring device operates by infra-red absorption gas analysis. The receiving chamber for the infra-red beam which has passed through the gas mixture is filled with sulphur hexafluoride (SF6). One pref. appts. consists of an infra-red emitter, a gas chamber contg. the gas mixture and a receiving chamber contg. the SF6. The SF6, as a substitute gas, is very close to water vapour in its properties in the wavelength range involved and has a high dew-point. Also, it is not normally present in industrial gases.</p> |
