Hilger Watts Theodolite: Manual

| Problem | Probable Cause (per manual) | Solution | | :--- | :--- | :--- | | | Clamp screw is over-tightened or dirt in the lower motion | Loosen clamp, use tangent screw (max 1 turn) | | Double vision in the micrometer | Interference in the optical prism | Clean external optics; internal requires a specialist | | Bubble won't center | Adjustment screws have shifted | Use the manual's "peg adjustment" method (two screws on the level vial) | | Graduations blurry | Incorrect focus of the reading microscope | Turn the knurled ring around the reading eyepiece |