Resolution No.12 (1979): 10 seconds digital recording for 1 minute means of geomagnetic data
IAGA, draws attention to the desirability of digital magnetic observatories using a sampling rate no slower than once every 10 seconds and asks these observatories to send these data to the World Data Centers as one-minute means (with clear identification of the method of averaging). These means should be centred on the minute (e.g. the first value within an hour is labelled 00h01m and is the mean calculated from 00h00m30s to 00h01m30s).