Owner`s manual

Page 28 of 40
Drawing : - TPC229
Issue : - 2
Date : - 10/12/13
Appendix I
Oven Drying Method for Determining Equilibrium Moisture Content
If an accurate moisture meter is not available, then moisture content can be
determined using the oven dry method. The oven dry method is actually more
accurate than moisture meters, but not very convenient. You do need and
accurate scale for weighing the wood samples and an oven (a baking oven
will do) to bake the samples.
Select a plank from the wood to be dried and cut 6 inches from each end and
discard these cutoffs. (They will be much drier than the rest of the piece).
Cut several one-inch pieces from one end until you have about a pound in
weight. Weigh these and record the wet weight. Weigh the remaining portion
of the plank and add it to the middle of the lumber stack in the kiln where it
can be retrieved periodically to monitor equilibrium.
Place the 1” sample in a 225ºF oven for 24 to 36 hours then weigh again.
This is the oven dry weight. Use the formula below to calculate the starting
EMC of the sample.
EMC = Wet Weight - Dry Weight x 100%
Dry Weight
The moisture content of the lumber in the stack can now easily be monitored
by periodically pulling the sample from the stack and weighing it. First,
however, calculate the future dry weight of the plank by using the EMC just
calculated.
Plank Dry Weight = Wet Weight
1 + EMC
100
Now having calculated the plank dry weight, use the formula above for
determining EMC to monitor drying progress.