Question

Select the correct combination of methods used to estimate solid volume of fire wood from the following.

• A. Xylometric method and single pole method
• B. Specific gravity method and shadow method
• C. Single pole method and shadow method
• D. Xylometric method and specific gravity method

Hint:

Xylometry measures volume via water displacement, and specific gravity calculates volume via dry weight and density. Both are standard physical methods for irregular stacked materials.

Answer 1

The Correct Option is D

Step 1: Understanding the Concept:
Firewood is typically stacked in irregular piles containing air spaces, making direct dimensional measurements highly inaccurate for determining actual wood volume.
To resolve this, foresters estimate the "solid volume" of wood within a stack by excluding the air voids between branches and logs.

Step 2: Detailed Explanation:
Let us analyze the biological and scientific methods used to estimate the solid volume of stacked wood:
1. Xylometric Method: This method relies on Archimedes' principle of water displacement.
The irregular firewood pieces are submerged in a specialized water-filled tank called a xylometer.
The volume of water displaced directly equals the absolute solid volume of the irregular wood pieces.
This is considered the most accurate direct physical method for measuring solid wood volume.
2. Specific Gravity Method: This is an indirect method based on weight-volume relationships.
The total weight of the firewood stack is recorded along with its moisture content.
By determining the average specific gravity (density) of wood samples from the stack, the solid volume is calculated using the formula:
\[ \text{Solid Volume} = \frac{\text{Oven-dry Weight}}{\text{Specific Gravity} \times \text{Density of Water}} \]
3. Single Pole and Shadow Methods: These are trigonometric and geometric techniques used to estimate the height of standing trees.
They have no application in calculating the volume of harvested, stacked firewood.
Thus, the combination of the xylometric method and the specific gravity method is the correct choice.

Step 3: Final Answer:
The correct combination of methods used to estimate the solid volume of firewood is the Xylometric method and the specific gravity method.