Respectively capable of logging temperature and temperature/relative humidity (RH) data, battery-operated OM-91 and OM-92 measure temperature to accuracy of ±0.3°C over 5 to 60°C range and ±2.0°C over full -30 to 80°C range. RH is measured to accuracy of ±3.0% RH over 20%–80% range and ±5.0% RH over 0%–100% range. Features immediate, delayed, or pushbutton start; real-time mode; user-configurable High and Low alarms; and USB interface for data transfer. Logging rate is software selectable.