The perimeter is an instrument for accurate charting of the field of vision. It consists of: A vertical stand on witch a metallic arc is pivoted. It also bear a circular black disc to read the meridian in witch the arc in shape of a semicircle with radius 330 mm. Its rotating in any direction and fix at any position with a tightening screw. The arc is graduated from 0º to 90º with a movable test object which is a white colour spot of size 10mm diameter painted on a circular disc it can be moved with arc. An adjustable chin rest and a detachable leveling bar is fixed in front of the metallic arc. A Scale and circular chart frame to hold the chart paper in position is provided at the back of the circular disc. A metallic graduated scale with a movable Pin-Punch pointer is fixed to mark on the perimeter chart paper.

Automatically records field to 90 degree in all meridians. The Carrier mechanism is smooth, silent and invisible. The patient perceives only the test object to move. Spring check, giving an Audible click to each 15 degree of rotation of the arc in either direction Renders close scrutiny of dial plate unnecessary, and ensures accurate registration. The device can be thrown out of action if silent movement is desired
The marker a needle is housed in a retractable tube, sprung to Sheath the pint when not actually marking. A set of interchangeable and permanent washable test objects is included with the instrument. The objects subtend angles of 4 degree, 2 degree, 1 degree, ½degre, ¼ degree and are in white, green and red blue objects in the last three sizes are also included. Supplies complete with Transformer to work on 220 Volt A/C mains With 100 charts.

With console with time and event channel and stimulator for human and animal experiments.

A Polygraph is an instrument that simultaneously records changes in physiological processes such as heart beat, Blood pressure, Respiration and electrical resistance.
It Comprises of Main Console, Transducers, Amplifiers and Accessories.