The working principle of different types of spirit level tool (2)

Laser level（spirit level tool)
A level that uses a laser beam instead of manual reading（spirit level tool). The laser beam emitted by the laser is introduced into the telescope barrel to emit a horizontal laser beam along the collimation axis.

Using the monochromaticity and coherence of laser, a glass or metal plate with a certain shading pattern, i.e. wave zone plate, can be assembled in front of the telescope objective to make the diffraction interference. After the telescope focusing, a bright and fine cross or circular laser spot is obtained within the focusing range of the zone plate, so as to aim the target more accurately. If the front and rear leveling rods are equipped with photoelectric receiving targets that can track automatically, leveling can be carried out. In construction survey and large component assembly, laser level is often used to establish horizontal plane or line.

Digital level gauge is the most advanced level gauge. With a special bar code level gauge, it can automatically obtain the bar code reading of the level gauge through the built-in digital imaging system in the instrument, and there is no need for manual reading. This instrument can greatly reduce the labor intensity of Surveying and mapping operation, avoid artificial subjective reading error, and improve the measurement accuracy and efficiency.

Electronic level(spirit level tool)

Electronic level, also known as digital level, is developed on the basis of automatic Anping level. It adopts bar code ruler. The bar code patterns of ruler codes of various manufacturers are different and cannot be used interchangeably. Before 2013, the collimation scale and focusing still need to be carried out visually. After manual collimation and focusing, on the one hand, the scale bar code is imaged on the telescope differentiation plate for visual observation. On the other hand, through the spectroscope of the telescope, the scale bar code is imaged on the photoelectric sensor (also known as detector), that is, the linear CCD device for electronic reading. Therefore, if the traditional level is used, the electronic level can be used like the ordinary automatic leveling level. However, the measurement accuracy is lower than that of electronic measurement. In particular, the precision electronic level has lower accuracy when used as an ordinary automatic leveling level because there is no optical micrometer.