| 摘要 |
PURPOSE:To make a detector of an infrared absorption type humidity fluctuation meter compact, to enhance the measuring accuracy of the detector and to elongate the life of the apparatus. CONSTITUTION:This infrared absorption type humidity fluctuation meter comprises a detector A and a meter body B. The detector A consists of a light projecting head 10 and a light receiving head 20, but the light projecting head 10 has no chopper blade or chopping motor. On the other hand, the meter body B is provided with a chopping circuit 42 which generates a 10 Hz gate signal to a light power source circuit 41. Accordingly, a current to a tungsten lamp 12 of the light projecting head 10 is turned ON/OFF, thereby to turn ON/OFF the tungsten lamp 12. |
