Technical indicators and functions of photoelectric range finder
The maximum range of the short-range infrared photoelectric range finder is 2 500m, and the distance measurement accuracy can reach ± (3mm+2×10-6×D) (where D is the measured distance); the minimum reading is 1 mm; the instrument is equipped with automatic The light intensity adjustment device can also manually adjust the light intensity when measuring in complex environments; the temperature, air pressure and prism constant can be input to automatically correct the result; the vertical angle can be input to automatically calculate the horizontal distance and height difference; the distance can be preset Carry out alignment stakeout; if you input the station coordinates and elevation, it can automatically calculate the coordinates and elevation of the observation point. The distance measurement method includes normal measurement and tracking measurement. The normal measurement takes 3s, and the average value of several measurements can be displayed; the tracking measurement takes 0.8s, and the distance measurement is automatically repeated at regular intervals.
Operation and use of photoelectric distance meter
First place the theodolite on the measuring station, after centering and leveling, install the main unit of the rangefinder on the theodolite bracket, lock it with the connector fixing screw, insert the battery into the bottom of the main unit, and fasten it. Place the reflective prism at the target point, center it, level it, and make the mirror surface face the host.
Observe vertical angle, air temperature and air pressure
Sight the center of the target plate with the cross wire of the theodolite, and measure the vertical angle α. At the same time, observe and record the temperature and barometer readings. Observing the vertical angle, air temperature and air pressure, the purpose is to correct the slant distance measured by the range finder, such as tilt correction, temperature correction and air pressure correction, so as to obtain the correct horizontal distance.
Sources of Ranging Errors of Photoelectric Rangefinders
(1) Proportional error: an error proportional to the measured distance length, mainly caused by frequency error, atmospheric refractive index error and vacuum light velocity measurement error to the ranging result. The influence of the speed of light measurement error on the ranging value is negligible.
(2) Fixed error: the inherent error of the instrument, which has nothing to do with the measured distance length, including the verification error of the zero point error, the centering error between the instrument and the mirror, the phase measurement error, the amplitude and phase error, the phase inhomogeneity error of the luminous tube and cycle error. The periodic error mainly comes from the same-frequency interference of the photoelectric signal inside the instrument, and the size of the error occurs repeatedly based on the length of the precision measuring ruler.
