Use of Distributed Temperature Sensing Technology to Characterize Fire Behavior.

Douglas Cram,Carlos Ochoa,Christine Hatch,Scott Tyler

doi:10.3390/s16101712

Abstract

We evaluated the potential of a fiber optic cable connected to distributed temperature sensing (DTS) technology to withstand wildland fire conditions and quantify fire behavior parameters. We used a custom-made ‘fire cable’ consisting of three optical fibers coated with three different materials—acrylate, copper and polyimide. The 150-m cable was deployed in grasslands and burned in three prescribed fires. The DTS system recorded fire cable output every three seconds and integrated temperatures every 50.6 cm. Results indicated the fire cable was physically capable of withstanding repeated rugged use. Fiber coating materials withstood temperatures up to 422 °C. Changes in fiber attenuation following fire were near zero (−0.81 to 0.12 dB/km) indicating essentially no change in light gain or loss as a function of distance or fire intensity over the length of the fire cable. Results indicated fire cable and DTS technology have potential to quantify fire environment parameters such as heat duration and rate of spread but additional experimentation and analysis are required to determine efficacy and response times. This study adds understanding of DTS and fire cable technology as a potential new method for characterizing fire behavior parameters at greater temporal and spatial scales.

Highlights

Fire science, effects, and modeling research require measures of fire behavior parameters such as fireline intensity, heat duration, and rates of spread [1,2]
As for the copper coated fiber, while the attenuation signature was logarithmic in shape—which is unusual for optical fibers—the change in attenuation was minor (Figure 4, Table 1)
We believe the logarithmic shape of the attenuation signal was an artifact of the manufacturing process as this condition existed before prescribed burns were conducted

Summary

Introduction

Effects, and modeling research require measures of fire behavior parameters such as fireline intensity, heat duration, and rates of spread [1,2] Quantifying these parameters is challenging in the laboratory and notoriously difficult in the field where instrument limitations, variations in fuel characteristics, and the turbulent nature of fluid dynamics and combustion lead to drastic variations over time and space. Options for quantifying these parameters include remotely sensed data from instruments mounted on aircraft or satellites with large pixel footprints or ground-based sensors within or above the flames [2]. Filling the gap in the spatial domain as well as the temporal scale can be critical to improving our understanding of fire behavior in wildland fuels.

Objectives

Methods

Results

Conclusion