SL5x USB Series data loggers are single channel and self contained temperature data logger with a battery life of up to 10 years or 1 million samples, depending on the ambient environment and the sampling rate.

These loggers plug directly into the USB port of the computer for configuration. They can then be removed from the USB slot and placed where monitoring is required. When the monitoring is complete, the data logger can be placed back in the USB slot for data retrieval. Depending on the model chosen, they have the ability to record up to 8,000 data points and have a measuring temperature  range  of -10°C  to +85°C and
0 to 95%RH.

Data downloaded to PC can be analyzed using TempIT software downloadable from this site.