The Loggers are designed for operation in warehouses, chambers, fridges and freezers. Loggers have internal RH sensor and either an internal or external temperature sensor. There is an option to read 4/20mA, 0-10v or contact switch inputs. Internal RH Sensor: Range 0-100%RH, Accuracy 2%RH Internal Temperature: Range -20°C to 60°C, Accuracy 0.5°C External Temperature: Range -200°C to 200°C, Accuracy 0.1°C to 0.3°C Battery Life: e.g. 2 years @ 1 min sample rate The loggers store up to 10,000 samples per sensor permitting the operation as a data logger if RF communication is not possible, e.g. one logger placed in a warehouse exhaust HVAC duct. The logger will resume transmitting data once it is in RF communication with the base station or other logger.