系统功能

采用热扩散技术测量植物茎干茎流速度，特别适用于茎干较粗的树木和高大植物。若配合其它传感器使用，可测量环境因子（空气温湿度，光合有效辐射、土壤温湿度等）影响下的植物茎流。

工作原理

利用Granier热扩散传感器（TDP）原理，把2根热电偶探针直接插入边材，上面的探针包含1个电加热器，下面的探针作为参照，测量加热探针和参照探针之间的温差dT。根据dT和零茎流时的dTm，应用Granier模型，可以直接得到每个时刻的茎流速率，再根据边材面积求出茎流通量。

对于郁闭冠层下长势一致的树木，每棵树只需一个传感器。对于不规则冠层或混合树种，大树的茎流速率在树周不同方向上存在差异，一棵树需要使用多个传感器才能准确测量茎流。直径在75~150 mm的树木，每棵树通常需安装2套传感器；直径在150~440 mm的树木，每棵树安装4套传感器。

系统特点

双探针，Granier砖利设计

探针易插拔，可重复使用

恒温加热，采用热扩散方法，而不是准确度较差的热脉冲方法

可以连续测量（热脉冲方法不可以，有等待周期）

应用案例

（1）西北农林科技大学 秦岭

参考文献

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