Barnard Holly R, Findley Matthew C, Csavina Janae
Department of Geography, Institute of Arctic and Alpine Research, University of Colorado at Boulder, Campus Box 450, Boulder, CO 80309, USA
Department of Geography, Institute of Arctic and Alpine Research, University of Colorado at Boulder, Campus Box 450, Boulder, CO 80309, USA.
Tree Physiol. 2014 Jun;34(6):640-5. doi: 10.1093/treephys/tpu044. Epub 2014 Jun 16.
Photosynthetically active radiation (PAR, 400-700 nm) is one of the primary controls of forest carbon and water relations. In complex terrain, PAR has high spatial variability. Given the high cost of commercial datalogging equipment, spatially distributed measurements of PAR have been typically modeled using geographic coordinates and terrain indices. Here, we present a design for a low-cost, field-deployable device for measuring and recording PAR built around an Arduino microcontroller-named PARduino. PARduino provides for widely distributed sensor arrays and tests the feasibility of using open-source, hobbyist-grade electronics for collecting scientific data. PARduino components include a quantum sensor, an EME Systems signal converter/amplifier and an Arduino Pro Mini microcontroller. Additional components include a real-time clock, a microSD Flash memory card and a custom printed circuit board. The components were selected for ease of assembly. We found strong agreement between the PARduino datalogger system and National Institute of Standards and Technology traceable sensors logged by an industry standard datalogger (slope = 0.99, SE < 0.01, P < 0.01; intercept = - 14.84, SE = 0.78, P < 0.01). The average difference between the two systems was 22.0 µmol m(-2) s(-1) with PARduino typically underestimating PAR. The average percentage difference between systems was 3.49%. On average, PARduino performed within the factory absolute calibration of the PAR sensor; however, larger errors occurred at low PAR levels. Using open-source technologies such as this can make it possible to develop a spatially distributed sensor network within the constraints of a typical research budget.
光合有效辐射（PAR，400 - 700纳米）是森林碳与水分关系的主要控制因素之一。在复杂地形中，PAR具有很高的空间变异性。鉴于商业数据记录设备成本高昂，PAR的空间分布测量通常使用地理坐标和地形指数进行建模。在此，我们展示了一种围绕Arduino微控制器构建的低成本、可现场部署的用于测量和记录PAR的设备设计——名为PARduino。PARduino可实现广泛分布的传感器阵列，并测试了使用开源、爱好者级电子设备收集科学数据的可行性。PARduino组件包括一个量子传感器、一个EME Systems信号转换器/放大器和一个Arduino Pro Mini微控制器。其他组件包括一个实时时钟、一张微型SD闪存卡和一块定制印刷电路板。这些组件因易于组装而被选用。我们发现PARduino数据记录系统与由行业标准数据记录器记录的可溯源至美国国家标准与技术研究院的传感器之间具有很强的一致性（斜率 = 0.99，标准误差 < 0.01，P < 0.01；截距 = - 14.84，标准误差 = 0.78，P < 0.01）。两个系统之间的平均差异为22.0微摩尔·米⁻²·秒⁻¹，PARduino通常低估PAR。系统之间的平均百分比差异为3.49%。平均而言，PARduino的表现处于PAR传感器的工厂绝对校准范围内；然而，在低PAR水平时会出现较大误差。使用这样的开源技术能够在典型研究预算的限制内开发出空间分布式传感器网络。
