One year experience with the CMVS 2 magnetic variation station

A year's operation of a digitally recording variometer (CMVS 2) employing a Bobrov magnetometer is described. The equipment provides hourly mean values of the geomagnetic component on paper tape. It has a range of outputs including analogue recording of the field variations which can be measured in the range 0–1999.9 nT with a sensitivity of 0.1 nT. After a running in period of some months the standard deviation of baseline values is in the range 1.5–2nT with a drift rate of about 2nT per month.