| タイトル | Fast, high sensitivity dewpoint hygrometer |
| 本文（外部サイト） | http://hdl.handle.net/2060/20080004590 |
| 著者（英） | Hoenk, Michael E. |
| 著者所属（英） | California Inst. of Tech. |
| 発行日 | 1998-04-14 |
| 言語 | eng |
| 内容記述 | A dewpoint/frostpoint hygrometer that uses a surface moisture-sensitive sensor as part of an RF oscillator circuit with feedback control of the sensor temperature to maintain equilibrium at the sensor surface between ambient water vapor and condensed water/ice. The invention is preferably implemented using a surface acoustic wave (SAW) device in an RF oscillator circuit configured to generate a condensation-dependent output signal, a temperature sensor to measure the temperature of the SAW device and to distinguish between condensation-dependent and temperature-dependent signals, a temperature regulating device to control the temperature of the SAW device, and a feedback control system configured to keep the condensation-dependent signal nearly constant over time in the presence of time-varying humidity, corrected for temperature. The effect of this response is to heat or cool the surface moisture-sensitive device, which shifts the equilibrium with respect to evaporation and condensation at the surface of the device. The equilibrium temperature under feedback control is a measure of dewpoint or frostpoint. |
| NASA分類 | Instrumentation and Photography |
| 権利 | No Copyright |
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