| 摘要 |
<p>PURPOSE:To accurately measure the humidity of the inside of piping even when a light-emitting or light-receiving device and a reflecting plate are stained by reflecting the radiated near infrared radiation at a light receiving device when the light receiving device is in its positions near and away from a light emitting device, and calculating the humidity from the amount of the near infrared radiation reflected. CONSTITUTION:Near infrared rays of such wavelength as to be absorbed into water are converted to light generated from a light-emitting element 7 serving as a light-emitting device and are introduced into a two-beam optical fiber 9 via a filter lens 8 which allows transmission of only the light of that wavelength therethrough and are applied to piping 1 from the light-emitting surface of a two-beam optical fiber connector 2. The near infrared rays applied are reflected when the reflecting plate 6 of a vane 5 rotated by gas flow within the piping 1 faces the rays while in its positions near and away from the two-beam optical fiber connector 2, and are alternately transmitted through the two-beam optical fiber 9 from the light receiving face of the two-beam light fiber connector 2 and received by a light receiving element 10 serving as a light receiving device and then an electric signal proportional to the amount of the light received is generated. The electric signal is input to a calculating device 12 via an amplifier 11. The calculating device 12 calculates the moisture of the inside of the piping 1 from the difference between levels of reflected light alternately input thereto.</p> |
