Characteristic:
With changing projection reading for eyepiece type it is convenient for use. With employing wax screen and setting magnifier before the screen, therefore it can improve the imago quality and whole viewfield obtains even brightness itself.
A heat-insulating glass is set in front of the optical system, the temperature of the instrument will not change very much, and then indication stability is increased. The reading system adopts a method of that the graduation of the mm scale, which can be centered in a set of double lines, thereby sighting accuracy is increased. If an optimeter tube is built on its tail tube, it become a horizontal optimeter.
