Presenter: Lexi DeFord
Authors: Alexis DeFord, Eric Pardyjak, Rob Stoll
Faculty Advisor: Eric Pardyjak
Institution: University of Utah
Accurate measurement of ambient air temperature is a critical component of most ecosystem monitoring and management efforts. This task is complicated due to solar radiation which heats the air temperature sensor body causing it to record temperatures in excess of the true air temperature. The traditional way to protect against this kind of interference is to use a passive radiation shield that houses the sensor inside layered shelves of material so that ambient air can still reach the sensor while blocking the majority of solar radiation. However, past research indicates that sufficient solar radiation can still penetrate most shield designs causing significant measurement errors under low wind conditions. An alternative method to mitigate this is to aspirate the sensor using a fan to force air movement over the sensor body. Aspirated temperature sensing units are available to buy commercially, but they can be expensive, consume a significant amount of power, and be difficult to integrate with existing hardware and software of low-cost measurement systems. Here, we present the design and validation of a low cost, low power aspirated temperature sensing unit designed to integrate with custom-built local energy-budget measurement system (LEMS), a low-cost distributed sensor platform developed at the University of Utah. The design uses off the shelf, inexpensive components (fan, sensing element, etc.) combined with a custom designed 3D printed housing that enables rapid assembly. This aspirated housing unit has been evaluated with comparison data against Mesonet data.