The customer can control the computer by using cellphone jammer

When two beams of light optical path difference of an odd multiple of half wavelength of the laser, two-beam light waves cancel each other out, and the formation of dark stripes on the receiver. A result, the two-beam synthesis of light intensity to strengthen or weaken is completely determined by two-beam optical path difference, while the fixed optical path of beam 1, beam 2, the optical path with the moving distance of the mobile prism. Therefore, by the shading of the interference fringes can be directly measured by the mobile moving distance of the prism. Laser interferometric measurement setup is shown in Figure 3.26. Thus, the laser interferometer ranging can only measure the distance traveled by the prism (ie, the relative distance). First mobile prism placed in the points a known distance (called the reference distance) (eg, laser tracker, the Bird's Nest), and then move, as long as it will interfere with the measured relative distance with the reference distance can be obtained absolute distance. And the projection screen can display various contents the customer wanna present by  green laser pointer .
The laser tracker can directly measure the three-dimensional coordinates of space points, these three-dimensional coordinates in the instrument coordinate system of the laser tracker. The coordinate system is defined as: the center of the track header as the origin 0 reading on the dial the direction of the X-axis upward in the direction of the dial plane normal to the Z-axis, Y-axis to the right hand coordinate system rules to determine, so the establishment of from the instrument coordinate system, shown in Figure 3.27. Figure 3.27 Laser Tracker coordinate measuring principle. Polar coordinate measurement. As shown in Figure 3.27, when the operator reflector (Bird's Nest distance from the center of the instrument plus) out from the nest tracker, and move in the space, the instrument automatically tracks the reflector, recorded simultaneously interfere with the ranging value D and the angle on the horizontal circle and vertical circle value, V. According to these three observations, the polar coordinate measuring principle can be a point in space three-dimensional Cartesian coordinates (x, y, z). The reason that green laser pointer is so popular is it is very practical in use.
The basic components of laser tracker. The laser tracker is to provide a variety of measurement data and the systematic error correction, it can be divided into five parts: the angle measurement part. Including the horizontal circle, vertical circle, stepping motor and reading system, similar to the total station angle measurement devices in automatic target recognition capabilities. Horizontal and vertical circle are grating incremental measuring angle encoder, segments portray number 18000, the goniometer nominal accuracy of better than ± 2.5 degrees, angle measurement sampling rate up to 1000 times / s measuring static target, multiple measurements averaged to eliminate the fluctuations in the atmosphere. Distance measurement part. Including interferometry distance measuring device (IFM), Bird's Nest (Birdbath), absolute distance measurement device (ADM) and reflector. Interference ranging using optical interferometry principle, to measure the distance by measuring the changes of the interference fringes change.  green laser pointer points at the target they want to highlight or show.
Therefore, the method of interference of the laser tracker distance measurement (IFM) can only measure the relative distance, such as the need to measure the center of the track head to the absolute distance of the points of space must be given a reference distance. The sensor unit has a fixed point is called the Bird's Nest (Home Point or Birdbath), tracking the head center to the nest distance (reference distance) is known, began to move the reflector from the Bird's Nest, the IFM measure the relative distance of the reflector to move coupled with the reference distance is the absolute distance. Reflector tracking mainly by the position detector (PSD); the reflector is reflected back into the light through the spectroscope when some light into the position detector, when the reflector moves, this part of the light will be in the position detection device to generate an offset value. According to the offset value, the position detector will control the motor rotation until the zero offset value, so as to achieve the purpose of tracking. The wireless presenter green laser pointer  includes page up function.
Including controllers, cables, and that part is used for data exchange between the computer and the laser tracker. The laser tracker during the measurement between the computer and the juice a lot of data exchange, and requires a high data transfer rate, so by the controller between the computer and the laser tracker in the form of a local area network (LAN) transmission data. Case, the adapter and the base for fixed-tracker and adjust its height. Laser Tracker application. Laser tracker by the measurement speed, high accuracy, easy to move and so on characteristics, widely used in large industrial product quality testing and laboratory facilities to install detection. Leica LTD500 laser tracker, the following as an introduction to the application of the automobile production plant. The customer can control the computer by using  cellphone jammer .