Perimeter (NU-238)

Automatically records field to 90 degrees 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 every 15 degrees 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 the silent movement is desired

The marker a needle is housed in a retractable tube, spring 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 degrees, 2 degrees, 1 degree, ½ degre, 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.