Abstract: Disclosed herein is a size-minimized data logger that also serves as a housing for a secure digital (SD) memory card. The SD card housing is located on one side of the data logger. The micro-SD card is used for recording raw or digital data and digitized event data. The data logger further includes, on the opposite side from the SD card housing, different functional units which are connected to one another. Exemplary functional units include an accelerometer, a magnetometer, a time unit, a temperature sensor and at least one analog/digital converter for conversion of measurement signals into digital input data, a processor unit for processing of data, a power supply source, an input interface for receiving signals or digital data and event data, and an output interface for outputting an indicator from the data logger.