A DIY Thermocouple Datalogger is Suitably Comparable to a Commercial System for Wildland Fire Research

Abstract

Thermocouple probes have long been standard equipment for wildland fire scientists. But despite substantial advancements in the electronic datalogger technology necessary to read and store data from thermocouples, the effective cost per thermocouple sensor of commercial systems has not decreased such that most researchers can afford to deploy enough sensors to account for the high degree of variability in wildland fire behavior. Because the equipment must endure the extreme conditions of wildland fire, is unlikely that any thermocouple datalogger system will be considered “cheap.” However, the growing number of applications of open-source, do-it-yourself (DIY) microcontroller systems in scientific research suggests these products might be employed in thermocouple datalogging systems if (1) their performance can be shown to be comparable to commercial systems and (2) they can be protected from exposure in the wildland fire environment. In this paper, we compare the performance of an Arduino MEGA microcontroller board relative to a Campbell Scientific CR1000, reading standard K-type metal overbraided ceramic fiber insulated thermocouple probes, under the constant temperature of a drying oven and the variable flame of a Bunsen burner. In both comparisons, we found that the variability among individual thermocouples, which are known to have a $$\pm\, 2\,^{\circ }\hbox {C}{-}6\,^{\circ }\hbox {C}$$ margin of error, was greater than between the dataloggers. We also describe a compact and mobile Arduino-based system capable of recording wildland fire flame temperatures in agris. In considering these three systems, it is clear that Arduino-based open-source, DIY components can support a compact, low-cost datalogger that accommodates more sensors for lower cost than proprietary commercial systems with no sacrifice in data quality. The combination of low-cost, multi-sensor units can contribute to better understanding of variability in wildland fire behavior.