Moisture Content (Junior Cert Wood Technology): Flashcards
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13 cards from this deck
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Practise the cards
13 cards from this deck
Moisture Content (MC) in timber
Moisture Content (MC) in timber
Measures moisture in wood compared to its dry weight
Why is MC essential for timber
Why is MC essential for timber
Determines stability and durability
Fibre Saturation Point (FSP)
Fibre Saturation Point (FSP)
Water in cell walls only, cell cavities are dry
Effect of moisture below FSP
Effect of moisture below FSP
Greatly affects wood's physical properties
Effect of high MC on wood strength
Effect of high MC on wood strength
Makes wood weaker
Effect of MC changes on dimensions
Effect of MC changes on dimensions
Wood expands or shrinks
Effect of wrong MC on durability
Effect of wrong MC on durability
Wood can rot or get pests
Oven drying method accuracy level
Oven drying method accuracy level
Very accurate
Oven drying method disadvantage
Oven drying method disadvantage
Time-consuming
Resistance-type metres best for
Resistance-type metres best for
Higher moisture levels
Capacitance-type metres features
Capacitance-type metres features
Fast for surface checks, not always spot on
MC calculation formula
MC calculation formula
% MC = (wet wt - dry wt) / dry wt × 100%
Environmental equilibrium in wood
Environmental equilibrium in wood
Wood's moisture matches the environment