The USDA, AMS, Cotton Division conducted a study in three classing facilities during the 1996 season to investigate the relationship of relative humidity in the air above and below cotton samples as they were conditioned on rapid conditioning units. The study results indicate that monitoring the conditioned air above and below the cotton samples is a useful tool for evaluating the rapid conditioning process. The study also revealed that potential exists for utilizing these measurements as an alternative means of assessing cotton sample conditioning.