Data loggers are electronic recording devices used to monitor parameters such as temperature and store data for analysis. Thermometers measure data as it happens, but data loggers continuously monitor events. In today's state of technology advancement, it does not seem realistic for one to stay overnight in a building in order to note the temperature every hour throughout the night. A data logger does this without sleep concerns, without mistakes and most importantly, with minimal human intervention.
The JR 1000 / JR 1001 data logger is the easiest to use electronic data logger available. With its precision calibrated internal temperature sensor, all you have to do is place the logger in the field and leave it. Once you have gathered the desired information, simply plug the logger into a PC's serial port and view the logged information.