公开(公告)号：US20220172969A1

公开(公告)日：2022-06-02

申请号：US17442529

申请日：2020-03-18

Applicant: FUJIKIN INCORPORATED

Inventor： Masaaki NAGASE ,  Keiichi HASEGAWA ,  Kouji NISHINO ,  Nobukazu IKEDA

IPC: H01L21/67 ,  G01N21/3504 ,  G01N21/33

Abstract: A concentration measurement device 20 for measuring the concentration of the a gas flowing through a junction block 14 connected to a plurality of gas supply lines includes a light source 40 for generating light incident to a flow path formed in the junction block, a photodetector 44 for receiving light emitting from the flow path, and an arithmetic control circuit 46 for determining the concentration of the gas flowing through the flow path based on the output of the photodetector, translucent incident windows 26 and 23 for making light from the light source incident to the flow path and, at least one of the translucent emitting windows 28 and 23 for emitting light passing through the flow path being sealed and fixed to the junction block 14.