Adjustments

TM5-6675-296-14

position, the vertical circle image appears in the

g. Focus the telescope as follows:

upper window. Simultaneously with either of the

(1) Direct the telescope toward a Uniformly

circle images, the image of the micrometer scale is

light background. Adjust the telescope eyepiece

always visible in the lower window.

(fig. 2-1, sheet 1) until the crosslines are sharp and

black.

2-4. Adjustments

NOTE

a. General. There are two types of adjustments

Observe the setting on the eyepiece. Tbis setting

made on the theodolite; instrument and operational

will remain constant for the same observer but will

adjustments. Instrument adjustments bring the

vary for other Observers.

theodolite into proper operating condition with

(2) Adjust the telescope focusing tube (fig.

respect to the interrelationship of its parts and are

2-1, sheet 1) to bring into view a clear image of

not normally made in the field. Operational ad-

the object being sighted.

justments bring the theodolite into proper

h. The horizontal and vertical circle reading

relationship with the terrain being surveyed, and

scales are both observed through the microscope

are required each time the theodolite is set up for

eyepiece (fig. 2-1, sheet 1). When the line of the

actual surveying operations. This paragraph covers

inverter knob (fig. 2-1, sheet 2) is in a horizontal

instrument adjustments.

position, the horizontal circle image (fig. 2-1, sheet

b. Circular Level. Refer to figure 2-7 and adjust

4) appears in the upper window. When the inverter

the circular level.

knob is turned with the line in the vertical

2-13