Use of a Flash Memory Card for Long-Term Geomagnetic Data Recording.

A compact data recorder using nonvolatile flash memory cards has been developed and is available for use in long-term and unmanned magnetometer data acquisition systems. A recently available flash memory card that consists of semiconductor memories is suitable for unmanned long-term recording in remote places difficult to visit frequently. This recorder collects 200 days of three-component 3-s-sampling geomagnetic data by using five pieces of a commonly sold 4-MB flash memory card and can be used for longer-term recording by using larger-capacity cards. Processing data from the cards to standard-format computer files is quick and smart, and no data are lost because of reading errors caused by physical damage.