Spotlight:Level

摘要

Level is a measure of the logarithm of the ratio of some quantity to a similar reference identified.As a tangible resource,a level is any bubble-tube device that is used to establish a horizontal line or plane.A level indicator determines the position of a liquid surface within a vessel.The indicating instrument can also show audio voltage level in an operating sound-recording system via a meter,neon lamp,or cathode ray tube.