Brunson 771 - Page 7

3 Operation and Adjustment Manual
doesn’tnecessarilymeanthatthelineswouldallintersectatthe
sameexactpointinspace.However,onourtransits,theselinesdo
intersect.Thisisanimportantcharacteristicwhenaccuracyispara‐
mount,particularlyatshorterdistances.Ofcourse,youcan’tsee
thisintersectionpoint–itisburiedinthemiddleofthetelescope.

Thesearethethreedistinctcharacteristicsthatourtelescopeshave
whichallowthemtomakeveryprecisemeasurementsoverrela‐
tivelyshortworkingdistances.However,thereisonemorevery
distinctivecharacteristicwhichseparatesOpticalToolingtransits
fromallothers–theopticalcross‐axis.Our76‐RH190hasaninfin‐
ity‐focusedtelescope,completewithasecondeyepieceandsecond
setofcrosswires,housedinthecrossaxis.Thiscross‐axistelescope
isusedinanumberofoperationstosetthemaintelescopeperpen‐
diculartoanothertelescopeoramirror(whichmaybemountedon
arotatingshaftorotherreferenceplane).
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Atransitisaveryflexiblemeasuringtool.Itcanestablishvertical
orhorizontalopticalplaneswhichareextremelyflat.Itcanestab‐
lishopticallineswhichareextremelystraight,extendinginanydi‐
rection.Oncetheseplanesandlinesareestab‐
lished,youcanusethemasreferencesfrom
whichtomeasureotherpointsofinterest.You
candeterminewhethermachinecomponents
areparallel,flat,level,square,orstraight.This
meansyoucanevaluatethegeometricrela‐
tionshipsrelatedtothealignmentofalmost
anypart,structuralcomponent,machine,tool,
surface,substrate,wall–orjustaboutany‐
thingelse.Averyfewexamplesofthiswould
be:

 Alignmentofbearingsandbearing
journals.
 Rollparallelisminpaperandmetals
mills,orprintingpresses
 Machinetoolevaluation:bedlevel‐
ing,bedflatness,geometricintegrity
ofspindlesand
othercomponents
 Layoutformachining
 Crankcasealignment
 Straightnessofenginebores,turbine
cases,torpedotubes,lineshafts,etc.
 Checkrelationshipsofrightangle
planes

TheOpticalToolinginstrumentsareextremely
flexible.Youcanusethemtomakejustabout
anymeasurementorgeometricevaluationthat
Figure1.2
Sowhatdoesatransitdo?