The microprocessor based devices record continuously or by set time intervals, i.e. every 1/2 hours, the in-stack and surrounding air properties, which govern the rate of drying and surface re-wetting (from morning dew) in the lumber stacks, The match-box size data collectors can either be removed and put back without disturbing the lumber stacks to download the data or can be plugged into a lap-top computer to read the data in situ. The recorded data, (external and within-stack) temperatures, relative humidities, and dew points are converted into drying rates to predict the lumber moisture contents in the air-drying stacks.

Lumber air-drying data was collected during the past four years in northern Louisiana and was used to develop a program to correlate the ambient air conditions, to lumber drying rates. The air drying was completed in 4-6 weeks in northern Louisiana, where the uncontrolled lumber equilibrium moisture contents (EMC) are between 12-16 W This shows, that the air-drying of hardwoods in northern Louisiana prior to kiln-drying requires only 1 to 11/2 months instead of the customary practice of 4-6 months of air-drying yard time.

The use of non-invasive microprocessor air-drying monitors can reduce the currently used air-drying time from 4-6 months to 1 to 11/2 months. This reduces the hardwood lumber production time from standing timber to finished kiln-dried product by 3-4 months and brings the hardwood industry closer to the concept of "just-in-time production", which can increase profits and market share.