The precision of the measurements of dry and wet-bulb temperature,wood moisture,and relative humidity in a wood drying kiln were evaluated.Several factors including temperature sensors,moisture sensors, measuring circuit,and personnel errors were considered to have effects on the precision of the system and were analyzed.The results indicated that adaptation of correct measuring devises,including both hardware and software,were key to solving the problems that influenced lumber drying precision.The precise determination of temperature,moisture level,and humidity could improve wood drying quality and reduce drying costs.