The circular scale is attached near theanalyzer and the range of measurement is 0-360Â°. A movable Vernier on the scaleenables reading of optical rotation to 60 seconds. Worm and gears combine roughand fine adjustment, provided with Half Wave Mica Plate, giving three partsfield for easy setting, adjustable half shadow angles. This instrument can beused on monochromatic light only. When light passes through a polarized sheetand then through the solution, the emerging light is observed through rotatablepolarized lens, analyzer which is used as eyepiece. The angle of light isrotated and read directly on the circular scale.