The closer wood is to the equilibrium moisture content the less it will move in service.
My first experience with metering wood was in cabinet and furniture work. Moisture content was critical to delivering a stable product. For instance glueing panel stock that was too green and then surfacing it led to unsightly gluelines or failures. Our suppliers had contracted to deliver wood at a specified moisture content, the meter was used to verify that the wood was suitable for our uses and that the supplier had met the terms of the contract before we accepted the load.
I bought the meter above when I was contracting with homeowners to assemble log home packages they had purchased. A number of suppliers were advertising that their materials were dried to some specified moisture content. This then becomes part of their purchase contract. I have sat in that most uncomfortable chair when a client decided to take the supplier to court. In that situation fingers begin to be pointed in every direction. The supplier pointed his at me. Unfortunately we do not live in a perfect world, I ordered that meter, in that case it is another documentary tool just like my camera.
In the photos above, several years later, another supplier and a similar situation. I explained to the clients' what had happened, what they had paid for, what they had recieved, what the possible repercussions were and ways to handle the situation. At the end of the conversation they chose to proceed. I took pictures of the meter to document the conditions. It's been over a dozen years, those clients are happy with their house.
I think I've explained how the meter can be used as a tool to further your knowledge of wood and how drying is progressing. It is a tool but it does take an understanding of wood to be of use.
An analogy might be helpful. My wife is a fine gardener, she has a degree in horticulture and worked as an ag tech at a large university. She takes soil samples... prior to planting by the signs. One does not exclude the other.
There are some things I've been thinking about regarding DL Bahler's paper. I suspected the changes were due to some form of extractive, this is pure speculation based on the gist of the paper and the mechanical property they chose to test. But, think about this, one example that is given in textbooks is the similar density of Sweetgum and Mahogany. Sweetgum has shrinkage values of 5.3 radial and 10.2% tangential. Mahogany, at the same density has shrinkage values of 3.7 & 5.1%... only about half the shrinkage of Sweetgum. The difference? Mahogany is loaded with extractives. These "bulk" the cells and prevent the fibers from being able to move together unimpeded. Less shrinkage due to the higher extractive content makes the mahogany more stable through moisture fluctuations and less likely to check while drying. I don't know if this is on the right track from the information given, just more grist for the mill.
