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The “right” moisture content depends on the final use of the wood and is
climate-driven. Recommended moisture content for indoor woodworking /
furniture ranges from 6%-9%. Outdoor construction grade lumber is usually
19% or less; 10%-15% for safe painting or staining.
Corrections for Specific Gravity (SG)
Measurements obtained with capacitance type moisture meters such as ProScan are
greatly influenced by the specific gravity of the material (specifically the wood) being
measured. Materials with higher specific gravity produce higher moisture readings than
materials with lower specific gravity at the same moisture content. Since ProScan is
calibrated for wood at a specific gravity (SG) of 0.46, a correction is required when
measuring wood species with SG values other than 0.46. At the end of this manual you
will find a listing of common species with published average values for SG and also a
table to correct meter readings for wood species. Use these values with the knowledge
that specific gravity varies within a single species and may even vary within the same
board. The following resources can be helpful if you are working with a species that is
not included in these tables. When referring to published data use the SG values based
on green volume and oven-
dry weight (sometimes referred to as “green basis”).
www.wood-database.com
www.fpl.fs.fed.us/
(Wood Handbook 2010)
www.woodworkerssource.com
HELPFUL TIPS FOR USING TECHSCAN TO MEASURE RELATIVE MOISTURE
LEVELS IN NON-WOOD MATERIALS:
Set the scale to “reF”. The 0-100 reference scale is for relative wet/dry
indications only. The numbers on this scale are relative, or qualitative
indications of moisture levels
– not % moisture content.
Select when
testing building materials such as drywall, concrete, plaster, EIFS, etc.
Readings in the low end of the scale usually indicate a drier condition;
readings in the upper end of the scale usually indicate a higher moisture level
in the material.
