A Low-Cost Wireless Temperature Sensor: Evaluation for Use in Environmental Monitoring Applications (original) (raw)

A Low-Cost Wireless Temperature Sensor: Evaluation for Use in Environmental Monitoring Applications

A wide range of environmental applications would benefit from a dense network of air temperature observations. However with limitations of costs, existing siting guidelines and risk of damage, new methods are required to gain a high resolution understanding of spatio-temporal patterns of temperature for agricultural and urban meteorological phenomena such as the urban heat island. With the launch of a new generation of low cost sensors it is possible to deploy a network to monitor air temperature at finer spatial resolutions. Here we investigate the Aginova Sentinel Micro (ASM) sensor with a bespoke radiation shield (together < US$150) which can provide secure near-real-time air temperature data to a server utilising existing (or user deployed) Wireless Fidelity (Wi-Fi) networks. This makes it ideally suited for deployment where wireless communications readily exist, notably urban areas. Assessment of the performance of the ASM relative to traceable standards in a water bath and atmospheric chamber show it to have good measurement accuracy with mean errors < ± 0.22 °C between -25 and 30 °C, with a time constant in ambient air of 110 ± 15 s. Subsequent field tests also showed the ASM (in the bespoke shield) had excellent performance (root-mean-square error = 0.13 °C) over a range of meteorological conditions relative to a traceable operational UK Met Office platinum resistance thermometer. These results indicate that the ASM and bespoke shield are more than fit-for-purpose for dense network deployment in environmental monitoring applications at relatively low cost compared to existing observation techniques.