Double-image rangefinders have linear graduations of 1 or 2 cm. As the distance increases, the image of the strokes of the scale of the rail decreases, becoming unclear. On this basis the maximum distances at measurement should not exceed 200-250 meters. To eliminate this disadvantage, the factory “Karel Zeiss” (GDR) has created a precision rangefinder double image as an attachment to theodolite Theo030, using the method of logarithmic tacheometry, proposed in 1878 Tihi...