| 摘要 |
PURPOSE:To enable accurate detection of relative humidity by reading changes in the oscillation frequency depending on a drop or a stop of the oscillation due to a dielectric relaxation based on the decrease in the resistance value due to humidity absorption of a piezo-electric body. CONSTITUTION:A piezo-electric body 2 is formed on the side of a tuning fork type vibrator body 1 and an electrode 3 thereon 2. The electrode 3' is preferably an island or net in the shape considering hygroscopicity and connected to a widely accepted oscillation circuit as surrounded by the broken line 4. As illustrated, the oscillation frequency decreases down to 65% in the relative humidity and the oscillation stops at this relative humidity of 65%. The percentage of the relative humidity can be confirmed by reading the oscillation frequency. The oscillation stops at the relative humidity of 65%, when the resistance value is close to 10<6>OMEGA. No piezo-electric property is indicated below this resistance value. Thus, the relative humidity can be detected exactly by reading changes in the oscillation frequency of the vibrator. |
