Topoghraphic Abney Level Offers Two Measuring Modes
Brass Topographic Abney Level features durable black finish and two interchangeable aluminum arcs. One arc is graduated in percentage of grade and degrees, 0–60º in both directions. The other arc is graduated in percentage of topographic scale (0 to ±100 ft.). Scale pointer remains stationary; aluminum arc moves with turn of small thumbscrew. Internal focusing by sliding knob on top of tube. 6-1/2"L.