GAS CONCENTRATION MEASUREMENT DEVICE

摘要

A gas concentration measurement device includes a light source that emits infrared light, a detector that detects the infrared light through a band pass filter, and a waveguide including a wave-guiding portion that includes a tubular inner peripheral surface, an entrance that introduces the infrared light from the light source to the wave-guiding portion, and an exit that guides the infrared light that passes through the wave-guiding portion toward the detector. A portion or the entirety of the inner peripheral surface of the wave-guiding portion includes a tapered region that includes a cross section that decreases along a direction extending from the entrance to the exit. The waveguide reflects the infrared light that enters the wave-guiding portion to reduce energy of the infrared light that is obliquely incident on the band pass filter.

主权项

1. A gas concentration measurement device comprising:
a light source that emits infrared light; a detector that detects the infrared light from the light source through a band pass filter; and a waveguide including a wave-guiding portion with a tubular inner peripheral surface, an entrance at one side of the wave-guiding portion and through which the infrared light from the light source is introduced, and an exit at the other side of the wave-guiding portion and guides the infrared light that passes through the wave-guiding portion toward the detector; wherein a portion or an entirety of the inner peripheral surface of the wave-guiding portion includes a tapered region with a cross section that decreases along a direction extending from the entrance to the exit; and the waveguide reflects the infrared light that enters the wave-guiding portion through the entrance in the tapered region to reduce energy of the infrared light that is obliquely incident on the band pass filter.