| 摘要 |
<p>PURPOSE:To make it unnecessary to attach a device having a light source to an object of measurement, to make an apparatus small in size and to save power by measuring infrared rays emitted by a substance itself. CONSTITUTION:All infared rays led by an optical fiber 5 are led out to a humid ity measuring unit 6 through an opening 7 of the measuring unit. The measuring unit 6 is provided with a pyroelectric element 11 and a rotary plate 8, and the rotary plate 8 has band-pass filter lenses 10 for wavelengths to be absorbed by water, and through holes 9, in different numbers. The pyroelectric element 11 receives all infrared rays or near infrared rays alone and turns them into band electric signals. Then the signals are received by A/D 17 and a central processing device 18 through an amplifier circuit 12, a filter circuit 13 and rectifier circuits 15 and 16, and in the device 18, the received signals are com pared with data stored beforehand. Next, a humidity display unit 19 displays humidity in accordance with signals outputted from the device 18 and on the basis of comparison in the quantity of received light between all lights in an infrared band and only the near infrared rays of the wavelengths absorbed by water. According to this constitution, an apparatus can be made small in size and a power can be saved.</p> |
