fiber saturation point การใช้

The moisture content of wood below the fiber saturation point is a function of both relative humidity and temperature of surrounding air.
According to this US Forest Service document, " Wood is dimensionally stable when the moisture content is greater than the fiber saturation point . " Their statement may not have been meant with the precision needed for astronomical measurements, but at least Tycho seemed to agree : " The other parts are only wooden, but they have been combined and joined together in such an ingenious way-we have described above when we explained the armillae-that they cannot bend or change with changes of the air, and furthermore the whole is covered with painted canvas . "*