Pstitioning the receiving field stop of a laser range-finder with a correcting plate

During setting and adjusting a laser range-finder,it is oftenmet how to position the receiving field stop.The wrongposition of the stop will result in a decrease in theperformances of a range-finder.This paper describes amethod of positioning the receiving field stop with acorrecting plate.According to the method,the receiving fieldstop will be positioned by D ray (λ=5893Å)as long asthe correcting plate is inserted into the optical path ofthe laser receiver.This method has been proved to besuccessful in the real applications.