7910 - Laserfiche WebLink

Home Browse Search

op A.19010-4 $01W %Am ?lt9t . er.c PCQA +a Ma \:?s+ee Loan Ytlval: i+OSi -- g Ll!S A1Ma Wfi ?? ?:+cM: -Me "LL - ,cry • • ' ;. -1, PP- !M i "Ic" .? vw 'AarM Mt ?? Q.r++r s0l+r C &W. Caw Sim MW nPM ua gat .w :fto MR Figure A-1. ~ Line Drawing of an engineer's level. Setting Up the Level The safest- way of transporting a level is to keep it in its case. In the field, it is common practice to carry the tripod and level from place to place as a single unit. Special care should be exercised when moving the level in this fashion, particularly if the instrument is being carried across the river. It is a good idea for the rodman to accompnay the levelman across the river, prepared to grab the level should to levelman lose his balance or step into a hole. When mounting the level on the tripod, it is important that the level is screwed snugly to the tripod. If the level is mounted too loosely, the instrument is unstable and will be difficult or impossible to level. If the mount is too tight, the instrument may freeze to the tripod, or the.threads may be stripped. When setting up the tripod, the tripod leg bolts and wing nuts should be loose. The tripod should be set up in such a way t`at the platform is approximately level to start with. This will facilitiate leveling the instrument. If possible, determine the direction of sight- ing for most of the sights, and set one leg of the tripod in that di- rection. This will leave a space for the levelman to stand while sight- ing, without straddling one of the legs. On side hill setups, placing one leg on the uphill side and two on the downhill slope usually gives a stable setup Once the tripod is adequately p.-sitioned, the legs may be firmly pressed into the ground by stepping on the tripod leg spurs near the bottoms of the legs. Before leveling the instrument, be sure to re- tighten the tripod lag wing nuts - do not over-tighten.