- Title:
-
The Development and Testing of the Wiltronics T-H Fine Fuel Moisture Meter
- Date:
- April 1997
- Organisations
- DSE
- Authors:
- Karen Chatto and Kevin Tolhurst
- Location:
- Victoria, Australia
Overview
The Wiltronics T-H Fine Fuel Moisture Meter measures electrical resistance of a fine fuel sample, and converts this to a moisture content. This meter was developed specifically for the measurement of vegetation fuels, as opposed to grains and wood. There are numerous meters and methods available to measure or estimate moisture content, however there are none that are portable, accurate and capable of measuring below 10% and above 50% oven dry weight.This report describes the Wiltronics T-H Fine Fuel Moisture Meter, the procedure for operation of the meter, the testing of the meter, and the calibration procedure. Relationships between fuel moisture content and electrical resistance were established for nine dead surface fuel types. Two linear relationships for each fuel type were found, one for moisture contents less than 9% oven dry weight, and the other for moisture contents between 9 and 200% oven dry weight. Relationships between the conductivity of leachate of the different fuel types and coefficient/intercept values for the fuel moisture content calibration curves were also found. Conductivities of leachate of an additional thirty dead surface fuel types were measured.
Using the relationships between the coefficient/intercept values and conductivities of the original nine fuel types, fuel moisture content calibration curves were obtained for the additional fuel types. The effects of temperature and the method of grinding the fuel samples were found not to have a significant effect on the relationship between resistance and moisture content. However the uniformity and fineness of the ground material did influence the amount of variation between individual observations.
Field testing was carried out for a limited range of fuel types, and under restricted weather conditions. It was found that observations varied by 1% in the field as long as the average of at least three measurements is taken. The majority of the testing, both in the laboratory and in the field, is limited to dead surface fuels only. However, the Wiltronics T-H Fine Fuel Moisture Meter has the potential to measure live fuel moisture contents.
The Wiltronics T-H Fine Fuel Moisture Meter is portable, accurate and capable of measuring moisture contents between 3 and 200% oven dry weight for a wide range of fuel types, including live and dead fuels of pine, eucalypts and shrubs.
