Operation method: Hold the handle 1 of the instrument, align the index mark on the rotating prism 2 with the "0" mark on the reading ring 3 (hereinafter referred to as zeroing), and then look at the light source of the light bulb in front of you at the same time, which is 3~5 meters away (an ordinary flashlight can be used as the light source). Then one eye leaning on the surface of the Mars bar frame 4 end, through the instrument to observe the point light source, the other eye directly observe the point light source. At this time, one eye for a bright red light, the other eye for the light source point of light. If the light does not pass through the point of light, then there is a hidden tilt in both eyes. At this point, turn the small handwheel 5 until the bright red light passes through the point of light, and then read the value on the reading ring. The value read is the trigonometry of the occultation to be examined. Translated with DeepL.com (free version) After zeroing, according to the martens rod stripe groove vertical placement of the state of the instrument in front of the left (right) eye, at this time, the left (right) eye for a horizontal red bright light, the right (left) eye for the source of the light point. The point of light is located in the red bright light above (below), that is, the left eye on the hidden oblique; vice versa for the right eye on the hidden oblique (see Figure II). Turn the small handwheel 5 until the bright red light passes through the light point. Then read the number on the reading rin Translated with DeepL.com (free version)