| 摘要 |
PURPOSE:To enable to perform a high-precise detection of humidity by means of a simple constitution, by a method wherein a crest value discriminates only a part corresponding to a set humidity range from a pulse train whose crest value changes according to humidity, and this detects a humidity range. CONSTITUTION:A pulse S1 from a pulse generator 14, passing through a partial pressure point between a series resistance 15 and a humidity sensor 16 whose resistance value decreases as humidity increases, produces a pulse train S2 whose crest value decreases as humidity increases. The pulse train S2 is processed by operational amplifiers 17 and 18 whose set values differ corresponding to a humidity range, and the crest value produces discriminating signals D1 and D2 for discriminating only a part corresponding to a set humidity range. A set humidity range is detected by a simple constitution, eliminating the need for a smoothing coil, via a RS type FF31 consisting of inverters 24, 25, D type FF26, 27, and NAND gates 29, 30. The reduction in a pulse duty ratio between the pulse trains permits the improvement of a detection precision and enables to perform a high- precise detection of humidity. |
