Theodolite
An instrument for measuring horizontal and vertical angles. It is composed of telescope, horizontal dial, vertical dial and base. According to the reading equipment, it is divided into vernier theodolite, optical theodolite and electronic (automatic display) theodolite. Theodolites are widely used in control, topographic and construction setting out surveys. There are six models of Chinese theodolite series: dj07, DJ1, DJ2, DJ6, dj15 and dj60 ("DJ" stands for "geodetic theodolite", "07, 1, 2,..." are the mean square error of the horizontal direction of one measurement loop expressed in seconds). When special accessories are attached to the theodolite, it can be composed of laser theodolite, slope theodolite, etc. In addition, there are special gyro theodolites, mine theodolites, photographic theodolites, etc.
Level
An instrument for measuring the height difference between two points. It is composed of telescope, level gauge (or compensator) and base. By structure: fixed mirror level, rotating mirror level, micro tilt level and automatic leveling level. The level gauge is widely used in surveying work such as control, terrain and construction setting out. The series standards of Chinese level include: DS05, DS1, DS3, ds10, ds20 and other models ("DS" refers to "geodetic level", "05, 1, 3,..." refers to the accidental mean square error of the mean of leveling height difference per kilometer expressed in mm). When special accessories are attached to the level, it can form a laser level.
Plate instrument
The ground is the main instrument for manual mapping of large-scale topographic map. It is composed of collimator, flat plate, support and other components. Adding an electromagnetic wave ranging device to the collimator can make the operation more convenient and rapid.
Electromagnetic wave rangefinder
An instrument that measures the distance between two points by using electromagnetic wave to carry ranging signal. Those with a range of 5 ~ 20 kilometers are called medium range rangefinders, and those with a range of less than 5 kilometers are short-range rangefinders. The accuracy is generally 5mm + 5ppm, which has the characteristics of small size, portability and high accuracy. Since the 1960s, rangefinder has developed rapidly. Since the 1990s, the precision of the two-color precision photoelectric rangefinder has reached 0.1mm + 0.1ppm. Electromagnetic wave rangefinder has been widely used in control, terrain and construction setting out, which has doubled the field work efficiency and distance accuracy.