The reading can only betaken as soon as the air bubble is completely fixed.

   The value indicated on the level is the slope of the basic length with one meter long.

   If it is necessary.to measure the real slope value of alength L,it may be calculated by the following equation:

   Real slope value =Scale X LXReading value For example,scale value=0.02mm/m.L=200mm.reading value (bubble movement)=2 divisions,then:

Real slope value=0.02/1000x200X2=0.008mm.