Abstract: A data logger includes a housing containing at least one sensor; programmable controller including a pre-programmed Erasable Programmable Read Only Memory (EPROM) containing control instructions and sensor drivers for all sensors; a Random Access Memory (RAM) providing data storage for storing data from each sensor; a power supply; and electromagnetic transfer device for accessing the logger and recovering data from the data storage from external to the casing; the RAM being adapted to accept, from external to the housing and via the electro-magnetic transfer device, instructions on the sensor drivers to evoke a desired sample regime; the logger also including a power up coil is provided within the housing to enable power from the external to the housing to be supplied during programming and during recovery of data.