Data loggers consist of a programmable microprocessor, storage medium and interfaces controlled by an operating system. The measured data is acquired by sensors and digitized by an AD converter for storage. The data can be transmitted by cable via the known interfaces or by radio via Bluetooth, WLANs or IrDA.
Data is stored internally on hard disks( HDD) or solid-state drives( SSD) or on external storage media or in the cloud. The data recorded can be operating data, run times, events, bit patterns, measured values, pulses or counter values. Many physical quantities can be recorded with data loggers. For example, data for position determination, temperature, CO2 emission, air pressure, humidity, speed and many other variables. The recording of the measured values may well take place over longer recording periods of several months or years. The stored data is read out via interfaces for further processing. For the connection of sensors, a data logger can have several channels, so that several measured variables can be recorded simultaneously.
In addition to recording measured data for later analysis, data loggers are also used for monitoring, whereby events such as sudden temperature changes or the appearance of moisture are recorded and passed on to control systems. Special event loggers (event loggers) are offered on the market for these purposes. Data loggers are used in research and development, in lengthy field tests, as GPS log gers in the monitoring of transports, for error analysis and in quality development.