DescriptionThe OM-140 Series are low-cost, compact, battery powered temperature/humidity data loggers capable of unattended logging (recording) of the ambient temperature and relative humidity (RH) of an environment for days, weeks or months. The OM-144 data logger can also measure and optionally log surface temperatures spot-checked by a technician using the unit’s integral infrared (IR) thermometer. In addition, these units can also calculate and display absolute humidity levels in units of grains per pound (GPP) or g/kg. Also called mixing ratio, GPP is a more useful moisture metric than RH to water damage restorers. Using RH alone, a restorer might unknowingly introduce moist air—with a low RH but a high GPP—during a job’s drying phase.