; BCRA Grade 5 specification file ; tape error ; 95.44% of readings are within 0.1m (2 S.D.) *sd length 0.05 metres ; compass error ; 95.44% of readings are within 1 degree (2 S.D.) *sd bearing backbearing 0.5 degrees ; clino error ; 95.44% of readings are within 1 degree (2 S.D.) *sd gradient backgradient 0.5 degrees ; station position error ; 95.44% of positions are within 0.1m (2 S.D.) *sd position 0.05 metres