PROBLEM TO BE SOLVED: To accurately correct a CO2 density sensor for a plant cultivation facility in a short time.SOLUTION: A CO2 density sensor correction system 20 is provided on a facility 10 for mushroom cultivation, and is formed of a CO2 density sensor 40, a suction pump 42, a CO2 absorption part 50, three-way valves 44, 46, and plural pipelines P1-P7 with a control part 22 as a center. The suction pump 42 is driven always, and when a correction operation is performed, by switching the three-way valves 44, 46, as shown in Fig. 3 (B), a closed channel B, which is formed of the three-way valve 44→the pipeline P2→the CO2 density sensor 40→the pipeline P3→the three-way valve 46→the pipeline P6→the CO2 absorption part 50→the pipeline P7→the three-way valve 44, is formed. The CO2 density sensor 40 is corrected, in a state in which the CO2 density measured after passing of a certain time since formation of the channel B is zero. The correction can be accurately performed in a short time without deviation by outside air, and a small amount of air is circulated in the closed space, so that deterioration of the CO2 absorption agent is made slower and a replacement frequency is small.SELECTED DRAWING: Figure 3COPYRIGHT: (C)2018,JPO&INPIT【課題】植物栽培施設用のCO2濃度センサを、短い時間で正確に校正する。【解決手段】CO2濃度センサ校正システム20は、キノコ栽培の施設10に設けられており、制御部22を中心に、CO2濃度センサ40,吸引ポンプ42,CO2吸着部50,三方弁44及び46,複数の配管P1~P7により構成されている。吸引ポンプ42は常時駆動しておき、校正動作を行うときは、三方弁44,46の切替により、図3(B)に示すように、三方弁44→配管P2→CO2濃度センサ40→配管P3→三方弁46→配管P6→CO2吸着部50→配管P7→三方弁44で形成される閉じた流路Bを形成する。前記流路Bを形成してから一定時間経過後に測定されるCO2濃度をゼロとしてCO2濃度センサ40の校正を行う。外気によるズレがなく、正確に短時間で校正するとともに、少ない空気を閉空間で循環させるため、CO2吸着剤の劣化が遅く交換頻度が少なくてよい。【選択図】図3
