Ce manuel assemble les renseignements existants sur la technologie du séchage des placages. Il est destiné aux opérateurs de séchoirs, aux contremaîtres et aux gérants. Il est conçu spécialement pour les usines de l'Est du Canada mais contient des références aux essences et aux méthodes de séchage couramment utilisées dans l'Ouest canadien. Les sujets suivants sont abordés dans ce manuel: humidité du placage, hydromètres, processus de séchage, types de séchoirs, opération et entretien des séchoirs, incendies, pollution et défauts des placages causés par le séchage.
Correction factors are provided for the Delmhorst resistance-type moisture meters equipped with 2-pin insulated electrodes. These factors allow the operator to adjust the meter reading for a wood temperature range of -40 degree centigrade to 50 degree centigrade. Factors are provided for 12 softwood species and 14 hardwood species.
This study involved the on-site evaluation of commonly employed equipment and procedures for evaluation of moisture content in solid-wood products. Specifically, a DC-resistance and two RF-based moisture meters were evaluated. The main overall objective was to identify procedures or develop information to allow more accurate final MC estimates to be determined. Lodgepole pine lumber of 25 and 40 mm thicknesses was employed for the test Material was tested at three time intervals spanning from the completion of drying to approximately 30 hours after drying. Meter readings were compared against oven-dry moisture contents. In most situations the moisture meters employed tended to underestimate final moisture content with the error varying from close to zero up to about 3 percent. The errors observed seemed to be consistent for a given test. This opens the possibility of employing site-specific correction factors to obtain better estimates of oven-dry moisture content. Problems may still arise when comparing mill results of moisture tests against those performed elsewhere by customers and end users.
