PERIMETER PRIESTLEY SMITH: - The perimeter isan instrument for accurate charting of the field of vision. It consists of. Avertical stand on which a metallic arc is pivoted. It also bear a circularblack disc to read the meridian in which the arc in shape of a semicircle withradius 330 mm. Itâs rotating in any direction and fix at any position with atightening screw. The arc is graduated from 0Âº to 90Âº with a movable testobject which is a white color spot of size 10mm diameter painted on a circulardisc it can be moved with arc. An adjustable chin rest and a detachableleveling bar are fixed in front of the metallic arc. A scale and circular chartframe to hold the chart paper in position is provided at the back of thecircular disc. A metallic graduated scale with a movable pin-punch pointer isfixed to mark on the perimeter chart paper.
B No. 4353, Main Road, Near Geeta Gopal Temple,, Ambala Cantt, Haryana, 133001, India