| 摘要 |
<p>A system includes a moisture analyzer 10 configured to detect moisture in natural gas. The moisture analyzer comprises an absorption cell 20 that encloses and conducts the natural gas; a pressure control device 38 to reduce the pressure of the natural gas inside the cell; a light emitting device 12, preferably a laser, which transmits light through the gas inside the cell; and a photodetector 26 that detects the intensity of the transmitted light exiting the cell. The system preferably comprises circuitry to acquire and process a spectrum of the gas, from which the concentration of water vapour in the gas can be determined. The spectrum may be an absorption-based, a direct absorption, or a derivative spectrum. The spectrum may be based on photoacoustic, cavity ring down, or fluorescence spectroscopy. The pressure control device may comprise a vacuum pump or aspirator, and preferably reduces the pressure of the gas to less than 5 psia (34.5 kPa).</p> |
