摘要 |
The measurement rod is adjustable as to height, and when in accordance with a surveying instrument it is set in its correct height position, i.e. plus or minus zero on the double thermometer type scale. Any level differences are simply read at the next direct measurement point on the scale. This eliminates any risk of erroneous calculation arising from the use of measurement rods currently available. The height difference from the ground surface to plus or minus zero on the scale is read from an in-built measurement strip. The measurement rod can be produced in optional forms, i.e. with different sizes, different lengths on the double scale, possibility of extension, with or without scale illumination, with or without water pass, and with or without frame. (Provisional Basic advised week 85/05) |