The tripod is placed in the location where it is needed. The surveyor will press down on the legs' platforms to securely anchor the legs in soil or to force the feet to a low position on uneven, pock-marked pavement. Leg lengths are adjusted to bring the tripod head to a convenient height and make it roughly level.
Once the tripod is positioned and secure, the instrument is placed on the head. The mounting screw is pushed up under the instrument to engage the instrument's base and screwed tight when the instrument is in the correct position. The flat surface of the tripod head is called the foot plate and is used to support the adjustable feet of the instrument.
Positioning the tripod and ...view middle of the document...
Furthermore, the Brunton Pocket Transit, commonly employed for field measurements by geologists and archaeologists, has been in continuous use since 1894. Some types of transits do not measure vertical angles.
The builder's level is often mistaken for a transit, but it measures neither horizontal nor vertical angles. It uses a spirit level to set a telescope level to define a line of sight along a level plane.
Definition of STADIA ROD
: a graduated rod used with an instrument having stadia hairs to measure the distance from the observation point to the place where the rod is positioned by observation of the length of rod subtended by the distance between the stadia hairs when these are fixed or of the space between the stadia hairs when they are adjusted to cover a certain definite interval on the rod
A dumpy level, builder's auto level, leveling instrument, or automatic level is an optical instrument used to establish or check points in the same horizontal plane. It is used in surveying and building to transfer, measure, or set horizontal levels.
An alidade (archaic forms include alhidade,...