Laser rangefinders generally use two methods to measure distance: the pulse method and the phase method.

The process of pulse method ranging is as follows: the laser emitted by the rangefinder is reflected by the object to be measured and then received by the rangefinder, and the rangefinder records the time of the laser reciprocating. Half of the product of the speed of light and the reciprocating time is the distance between the rangefinder and the object being measured.

The accuracy of the distance measurement by the pulse method is generally about +/- 1 meter. In addition, the measurement blind area of this type of rangefinder is generally about 15 meters.

How to use the rangefinder:

1. Arrange the instrument

Arrange the theodolite on the measuring station first, after centering and leveling, place the main unit of the rangefinder on the theodolite bracket, fasten it with the fixing screw of the connector, insert the battery into the bottom of the main unit and fasten it. Arrange reflecting prisms at policy points, centered, leveled, and oriented toward the host.

2: 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 readings on the temperature and barometer. Observing the vertical angle, air temperature and air pressure, the purpose is to correct the slope distance measured by the rangefinder, and correct the slope, temperature and air pressure to obtain the correct horizontal distance.

3. Ranging preparation

Press the power key "PWR" to turn on, the host will self-check and flash the original set temperature, air pressure and prism constant value, after the self-check, it will flash "good".

If you want to correct the original set value, you can press the "TPC" key to input the temperature, pressure value or prism constant (usually input one by one through the "ENT" key and numeric keys). Under normal circumstances, it is only necessary to use the same type of reflector, the prism constant remains unchanged, and the temperature and air pressure may be different for each observation, which needs to be re-set.

4. Distance measurement

Dispatch the horizontal adjustment handwheel of the aiming axis of the main engine (or the horizontal fretting screw of the theodolite) and the pitch fretting screw of the main engine, so that the rangefinder telescope can be accurately aimed at the center of the prism. In the case of flashing "good", accurate aiming can also be judged according to the buzzer's movement. The stronger the signal, the greater the movement and movement. The rangefinder is slightly moved up and down, left and right, so that the buzzer's movement is Z largest, and the accurate aiming is ended. Appear"*".

Application areas of laser rangefinders

Laser rangefinders are now widely used in the following fields: electric power, water conservancy, communication, environment, construction, geology, police, fire protection, demolition, sailing, railways, anti-terrorism/military, agriculture, forestry, real estate, leisure/wild sports etc.