The Barnant temperature and humidity logger operates in three modes: two-channel temperature, humidity/temperature, and dewpoint/temperature. The compact unit features nonvolatile memory, storable setup conditions, thermocouple probes (type J, K, or T), logged/stored parameters, and peak/valley for each mode. The instrument is portable and is powered by two AA batteries or an optional ac power supply. Serial input/output provides printer and computer compatibility.