If you are looking for something easy to use, high quality and microprocessor based for data acquisition of temperature and relative humidity check out the Novus LogBox-RHT!
The Novus Automation LogBox-RHT-LCD is a dual channel data logger with built-in temperature and relative humidity sensors. These data loggers offer accurate and reliable operation in many applications - transportation, food storage, process auditing, pharmaceutical, HVAC and many more.
You can easily program the Novus LogBox-RHT-LCD using a handy infrared IR-LINK 3 interface connected to a USB port. Free LogChart II software gives you logger configuration, recorded data retrieval, plotting, historical analysis and it exports data to spreadsheets!