Data Loggers

Data Loggers are used to acquire and store information from sensors. The entire spectrum of data storage devices used topside have and can be housed in pressure vessels. These include hard disk drives, flash memory, video tape, etc. When brought to the surface, the logged data can be transferred to a computer or the memory can be removed for archiving. Factors to consider when selecting a data logger include how many sensors will be measured, for how long at what sampling rate, how much power is available, how much space is available, etc.
Environmental sensors and transducers often measure things such as temperature, pressure, sound or light, as voltages or current levels. These analog signals must be converted to digital ones for use by computers. The conversion, known as A/D conversion, is done by electronic sampling of the analog signals.
This function is often performed by a data acquisition board in a data logger. The board may have several input channels to take in data from more then one sensor.