How to calibrate the three-axis relationship of the distance measuring instrument
During the use of rangefinders, the relationship between the three axes of the rangefinders (telescope aiming axis, rangefinder transmitting axis, and receiving axis) often changes due to vibrations, collisions, and long-term operation and transportation. The conventional calibration methods are simple to operate, but the calibration results are not accurate enough.
1. Calibration principle
By measuring the angle values of the echo signal range in the horizontal and vertical directions of the distance measuring instrument, the correct readings of the dial at the four critical states (weakest echo signal) positions of the distance measuring instrument are calculated when the three-week relationship meets the requirements. After rotating the micro screw to the correct reading position on the dial, calibrate the return signal of the distance measuring instrument to a critical state, so that the corrected aiming mirror mark is at the center of the return signal range. Taking the three-axis relationship verification of DI2002 rangefinder as an example.
2. Inspection of horizontal parallelism
(1) Place a reflector around 200m away from the rangefinder, use a telescope to aim at the reflector mark, and read the horizontal dial reading A (145 ° 04'30 '').
(2) Slowly rotate the horizontal micro spiral of the theodolite to deviate the aiming direction from the reflector mark to the left, observe the changes in the return signal of the distance measuring instrument, until the return signal is in a critical state (the return signal constantly jumps between one grid and no signal), and read the level reading A (144 ° 57'59 '').
(3) Using the same method, measure the horizontal dial reading A (145 ° 07'37 '') when deviating from the critical state on the right side of the reflector mark
(4) Calculate the horizontal deviation angle according to the following formula:
3. Horizontal parallelism correction
(1) Calculate the correct angle value when deviating from the critical state on the left and right of the reflector mark using the following formula.
