4.Checkingand adjusting
Beforeleavingthefactory,eachcenterlineisproperlyadjusted,thecenterlineis
properlyadjusted,thecenterlinesmaydeviatefromproperpositionafter
transportation orlongtimeoperation.Sotocheckandadjustthemain centerlines is
necessarybeforemeasuring and surveying isfield work.
4.1 Correcttheparallelismforboth circlebubbleand verticalaxistosetthe
instrument on tripod,andtorotateleveling screwsuntil bubbleiscentered.If to rotate
theinstrument on 180 ,thebubbleremainscentered,bubbleposition iscorrect,
otherwiseif mustbecorrectedin following way.
a.Torotatefootscrew,enablingbubbletomovecentered,andit'smovementwill
behalfdeviationfromthe totalvalue.
b.Toadjustthebubbleadjustingscrew,enablingbubbleto movecentered,andrepeat
until thebubble doesnot movealong with rotatingof theinstrument.
