Development of a Low-Cost, 3D-Printed, Aspirated Air Temperature Measurement Radiation Shield

Abstract Accurate measurement of ambient air temperature is critical to numerous applications. This task is complicated by solar radiation which can heat the air temperature sensor body, causing it to record temperatures in excess of the true air temperature. The standard way to protect against this interference is to house the sensors in passive radiation shields which block the majority of solar radiation. However, solar radiation still heats the shield body which can then heat the sensor, causing measurement errors under low wind conditions. An alternative method is to aspirate the sensor using a fan to force air movement over the sensor body. Aspirated temperature sensing units are commercially available, but they can be expensive and consume a significant amount of power. Here, we present the design and initial rigorous testing of a low-cost, low-power aspirated temperature sensing unit designed to integrate with any low-cost distributed sensor platform. The design uses a freely available, custom-designed 3D-printed housing that enables rapid assembly. The new, open-source unit is shown to perform as well as passive shields and commercial aspirated shields of significantly higher cost. This success shows the potential of leveraging 3D printing technologies for other housing units. Further testing is needed to better quantify the long-term robustness of the shield. Significance Statement This paper describes a low-cost open-source aspirated radiation shield for accurately measuring air temperatures. While aspirated shields exist commercially, they can be expensive and energy intensive. The design presented here can be easily fabricated with an inexpensive low-power fan and low-cost 3D printing capabilities. The design results in temperature measurements that compare well with more expensive options.