You are here: Home
/ Publication Information
Title: Measuring duff moisture content in the field using a portable meter sensitive to dielectric permittivity
Author: Robichaud, Peter R.; Gasvoda, D. S.; Hungerford, Roger D.; Bilskie, J.; Ashmun, Louise E.; Reardon, J.
Source: International journal of wildland fire. 13(3): 343-353
Publication Series: Miscellaneous Publication
Description: Duff water content is an important consideration for fire managers when determining favourable timing for prescribed fire ignition. The duff consumption during burning depends largely on the duff water content at the time of ignition. A portable duff moisture meter was developed for real-time water content measurements of nonhomogenous material such as forest duff. Using circuitry developed from time and frequency domain reflectometry (TDR and FDR) technologies, this sensor measures a change in frequency that is responsive to the dielectric permittivity of the duff material placed in a sample chamber and compressed. Duff samples from four forest cover types—Douglas fir, larch, lodgepole pine and spruce/alpine fir—were used to calibrate the frequency output to volumetric water content. A second-order polynomial (R2 =0.97) provides the best fit of the data to volumetric water content. The accuracy of the duff moisture meter is ±1.5% at 30% volumetric water content and ±4% at 60% volumetric water content. The volumetric water content can readily be converted to gravimetric water content, which is used more frequently by fire managers and as an input to predictive models of duff consumption.
Keywords: duff moisture meter, forest floor, frequency domain reflectometry (FDR), prescribed fire, time domain reflectometry (TDR)
- We recommend that you also print this page and attach it to the printout of the article, to retain the full citation information.
- This article was written and prepared by U.S. Government employees on official time, and is therefore in the public domain.
- You may send email to email@example.com to request a hard copy of this publication. (Please specify exactly which publication you are requesting and your mailing address.)
XML: View XML
Robichaud, Peter R.; Gasvoda, D. S.; Hungerford, Roger D.; Bilskie, J.; Ashmun, Louise E.; Reardon, J. 2004. Measuring duff moisture content in the field using a portable meter sensitive to dielectric permittivity. International journal of wildland fire. 13(3): 343-353
Get the latest version of the Adobe Acrobat reader or Acrobat Reader for Windows with Search and Accessibility