A data logger is an electronic instrument that uses internal or external sensors to register and document data over time. For example, Dickson Data is one of the more well-known manufacturers in the US developing and launching data loggers to market for almost 100 years. In addition to the sensors, data loggers usually include a microprocessor, which interprets the environmental input from the sensors, and a digital storage device like a hard drive or flash drive that records—or “logs”—the data that the microprocessor produces.  Some data loggers need to be hard-plugged into a computer to extract the data; others can transmit data over wireless networks.