Theory

Adjustment which are performed at each set up of level trial to the actual work of taking observation called as temporary adjustment. Ones the instrument is permenantally adjustment than at each new position level is temporary adjustment in following operation to set axis of rotation process is also known as setting temporary adjustment for dumpy level are

a)    Setting up level

b)   Leveling of level

c)    Focusing and elemenation of parallar


Diagram




Procedure


Setting up level

In this operation first of all the level was taken out from box by holding in right hand and dumpy level is fixed at the top of tripod by turning round only the leveling head with the left hand. Length of tripod stand where spread in such a way so that level remains stable. Then the level screws were brought in the centre of their run and adjustment the height of instrument by moving the length so that levelle or level man to take reading easily.


Leveling of level

Telescope was turn so that it should be paralled to two legs pressed into the ground by third leg the longitudinal bubble was brought to the centre approximately and at this stage third leg was pressed into the ground. Accurate adjustment of level was done by moving telescope parallel to any pair of foot screw and applying the rule right in and left out moved the foot screw inward or outward and brought the bubble of longitudinal level in centre than telescope was moved 900 any clockwise manner so that it was exactly over the third foot screw. Here the bubble was placed the centre by its third foot screw by applying same rule.


Focusing and elemenation of parallax


Apparent movement of image of an object with respect to cross hair when image from by object glass does not falled in plane of dyform is called as parallax. It was tested by moving the eye up and down in case image fixed to cross-hair on movement of eye there is no parallax on the other hand it image goes same direction as that of eye there is parallax which is removed by focusing the eye piece of object tube a sheet of white paper present in front of object glass and seen to eye piece and by adjusting the eye piece in handout in its sockets. The crosshair wear made disting and clear.