290-UNIT 10 FUEL MOISTURE EXAM QUESTIONS WITH CORRECT ANSWERS LATEST UPDATE 2026
Living fuels, Variations in live fuels, Perennial and Annual Herbaceous Vegetation, Fuel Models with
live fuels, Crown Fires. - Answers Define critical live fuel moisture and thresholds for various fuel types
Estimation based on time of year
Live fuel sampling (oven dry method)
- (Wet-dry)/dry
Online data sources (WFAS) - Answers 3 methods for obtaining life fuel moisture
Fuel Moisture Exchange with the atmosphere
Equilibrium Moisture Content
Environmental Factors Influencing Fuel Moisture - Answers Define the relationship between RH, wind,
and moisture content of fine and large fuels.
Shaded vs unshaded (fuel temp)
Aspect (lowest FM on West)
Elevation (high=low FM)
Slope (slope % affects solar heating)
Wind (whatever is happening to fuel.. wind makes it faster) - Answers Environmental factors
influencing Fuel moisture
Precip can raise fine dead fuel moisture more rapidly.
Takes longer in large dead fuels
precipitation duration affects fine vs large differently.
-large will hold onto moisture longer, fine fuels get to saturation point then dry out quickly. - Answers
Explain how the amount and duration of precipitation and soil moisture affect moisture content of
fine and large fuels
- Answers The fuel moisture time-lag concept and its value to firefighters
it varies by size class
1hr
-calculated from fine dead fuel charts
-rough estimate
-oven dry
10hr
-fuel moisture sticks
-NFDRS outputs
-oven dry
100 and 1000
-NFDRS outputs
-oven dry
-calibrated moisture meter - Answers Describe how fuel moisture is determined for dead fuels in each
of the four timelag catagories
the fuel moisture content at which a fire will not spread, or spreads only sporadically
-High Moisture of Extinction= higher moisture needed to extinct (chemical plants)
-low moisture of extinction= lower moisture needed to extinct (grasses) - Answers Moisture of
Extinction
- Answers Determine fuel moisture content for fine dead 1-hour timelag fuels from fuel moisture
tables during daylight conditions.
The amount of water in a fuel, expressed as a percent of the oven dry weight of that fuel. -(wet
weight-dry weight)/dry weight - Answers Define fuel moisture content.
212 F - Answers What is the oven temp for drying fuels?
found in living plants
range is 30-300%
Living fuels, Variations in live fuels, Perennial and Annual Herbaceous Vegetation, Fuel Models with
live fuels, Crown Fires. - Answers Define critical live fuel moisture and thresholds for various fuel types
Estimation based on time of year
Live fuel sampling (oven dry method)
- (Wet-dry)/dry
Online data sources (WFAS) - Answers 3 methods for obtaining life fuel moisture
Fuel Moisture Exchange with the atmosphere
Equilibrium Moisture Content
Environmental Factors Influencing Fuel Moisture - Answers Define the relationship between RH, wind,
and moisture content of fine and large fuels.
Shaded vs unshaded (fuel temp)
Aspect (lowest FM on West)
Elevation (high=low FM)
Slope (slope % affects solar heating)
Wind (whatever is happening to fuel.. wind makes it faster) - Answers Environmental factors
influencing Fuel moisture
Precip can raise fine dead fuel moisture more rapidly.
Takes longer in large dead fuels
precipitation duration affects fine vs large differently.
-large will hold onto moisture longer, fine fuels get to saturation point then dry out quickly. - Answers
Explain how the amount and duration of precipitation and soil moisture affect moisture content of
fine and large fuels
- Answers The fuel moisture time-lag concept and its value to firefighters
it varies by size class
1hr
-calculated from fine dead fuel charts
-rough estimate
-oven dry
10hr
-fuel moisture sticks
-NFDRS outputs
-oven dry
100 and 1000
-NFDRS outputs
-oven dry
-calibrated moisture meter - Answers Describe how fuel moisture is determined for dead fuels in each
of the four timelag catagories
the fuel moisture content at which a fire will not spread, or spreads only sporadically
-High Moisture of Extinction= higher moisture needed to extinct (chemical plants)
-low moisture of extinction= lower moisture needed to extinct (grasses) - Answers Moisture of
Extinction
- Answers Determine fuel moisture content for fine dead 1-hour timelag fuels from fuel moisture
tables during daylight conditions.
The amount of water in a fuel, expressed as a percent of the oven dry weight of that fuel. -(wet
weight-dry weight)/dry weight - Answers Define fuel moisture content.
212 F - Answers What is the oven temp for drying fuels?
found in living plants
range is 30-300%
