气管材质和长度对农田小气候CO2/H2O分析仪读数稳定时间的影响

CO₂和H₂O气体浓度是农田小气候的2个重要指标，一般采用CO₂/H₂O分析仪进行测定，为减少人为干扰，需使用气管将待测区域气体传输至分析器，而气管的材质及其长度会影响CO₂/H₂O测定时读数稳定所需的时间。本研究采用8种常用材质的气管及5种气管长度进行双因素随机区组试验，以筛选CO₂/H₂O测定所需的最佳气管材质及长度。结果表明：不同材质气管测定CO₂浓度的稳定时间为9.20～11.47s，测定H₂O气体浓度的稳定时间为9.67～18.93s。利用主效可加互作可乘（Additive main effects and multi-plicative interaction，AMMI）模型对CO₂/H₂O气体浓度达到稳定的时间进行方差分析和稳定性分析发现，在CO₂浓度观测过程中，气管长度的固定效应导致的变异最大，材质次之，材质与长度互作效应较小；各材质中，CO₂读数稳定时间最短的为蠕动泵管；在H₂O气体浓度观测过程中，存在显著的材质和长度间的互作效应，其中材质的固定效应导致的变异最大，长度次之，PVC管的读数稳定时间最短。不同材质与不同长度的交互作用不同，每种材质对不同长度都有其特殊的适应性。因此，应根据测定指标，选择稳定时间短的材质和长度，以提高农田CO₂和H₂O气体浓度的测定效率。

Effect of Hose Material and Length on the Stability Time of CO2 /H2O Analyzer in Farmland Microclimate

Concentrations of CO₂ and H₂O are important indicators of farmland microclimate. When using CO₂ and H₂O analyzers to determine indicators in the field, the hose must be used to transfer the gas to the analyzer，but the material and length of the hose will affect the setting time and accuracy of the CO₂ and H₂O when they were determined. In this study, 8 hoses and 5 lengths were used to screen the best material and length for CO₂ and H₂O measurements. The results showed that the setting times of CO₂ in different material hoses were in 9.20−11.47s, and the setting times of H₂O were in 9.67−18.93s. The stability analysis of the setting time of CO₂ and H₂O using the AMMI model shows that in the CO₂ concentration stability, the fixed effect caused by the length was the largest, followed by the material, and the material and the length were mutually exclusive. The setting time of CO₂ concentration of the peristaltic pump tube in the material was the shortest; while in the setting time of H₂O concentration, there was a significant interaction effect between the material and the length, in which the fixed effect caused by the material was the largest, and the length in the second place, and the setting time of H₂O concentration of Polyvinyl chloride(PVC) pipe was the shortest. Different materials had different interactions with different lengths. Each material had its own special adaptability to different lengths. Therefore, in the test process, chose the material and length of the shortest setting time according to the required measurement indicators to ensure the accuracy and efficiency of the data.