Hand Level

The hand level, like all surveying levels, combines a level vial and a sighting device. Figure 15 shows the Locke level, a type of hand level. A horizontal line, called an index line, is provided in the sight tube as a reference line. The level vial is mounted atop a slot in the sighting tube in which a reflector  as set at a 45° angle. This permits the observer sighting through the tube to see the object, the position of the level bubble in the vial, and the index line at the same time.

To get the correct sighting through the tube, stand straight, using the height of your eye, if known, above the ground to find the target. When your eye height is not known, you can find it by sighting the rod at eye height in front of your body. Since the distances over which you sight a hand level are rather short, no magnification is provided in the tube.