Infrared photoelectric rangefinder structure and composition
Infrared rangefinder is mainly composed of modulated light emitting unit, receiving unit, phase measurement unit, counting display unit, logic control unit and power converter and other parts. Its light source is usually arsenic crop (GaAs) semiconductor light-emitting diodes. When a considerable amount of current forward through the GaAs diode P-N junction, P-N junction will be emitted in the wavelength of 0.72 μm, 0.94 μm of near-infrared light, which is due to the doped GaAs semiconductor electron-hole composite, the excess energy in the form of photons released and produced. And the intensity of the light emitted changes with the injection current. Therefore, it will be used as a rangefinder light source, you can change the size of the feed current on the intensity of the light emitted directly to the amplitude modulation, that is, this semiconductor light-emitting device both "radiation" a "modulation" dual function.
Used to receive modulated light infrared photoelectric detection conversion device is usually a silicon photodiode or avalanche photodiode, these devices have a "photovoltaic effect". When the external light irradiation to its P-N junction, due to the effect of photoelectric energy conversion in the P-N poles to produce a potential difference, the size of which varies with the intensity of the incident light.
The size of the difference will vary with the intensity of the incident light, thus playing the role of "demodulation".
Technical specifications and functions of photoelectric rangefinder
Short-range infrared photoelectric rangefinder has a maximum range of 2,500m, ranging accuracy of ± (3mm + 2 × 10-6 × D) (where D is the measured distance); minimum reading of 1 mm; the instrument is equipped with an automatic light intensity adjustment device, the measurement of the light intensity can be manually adjusted in complex environments; can be input into the temperature, barometric pressure and prismatic constants automatically correct the results; can be automatically calculated by inputting the vertical angle horizontal distance and height difference; can be calculated by distance and height difference; can be used to measure the distance to a distance of 1,000 metres. Distance and elevation difference can be calculated automatically by inputting vertical angle; Line setting can be carried out through distance presetting; Coordinates and elevation of observation points can be calculated automatically if station coordinates and elevation are inputted. There are normal measurement and tracking measurement, in which the time required for normal measurement is 3s and the average value of several measurements can be displayed; the time required for tracking measurement is 0.8s, and the distance measurement is repeated automatically at certain time intervals.
