At a distance of 570mm, a 1 degree check should measure out to be 10 x 10 mm.
If this is not the case, please follow the calibration instructions below:
Navigate to Configure System (from the START window) and open the HARDWARE folder; scroll until you see VGA Pattern Stimulator, double click to drop down. Find Calibrate Monitor and click on the blue monitor icon to open up a separate pop-out window.
Enter into the View Angle tab of this pop-out window. Click on the 100*100 Square button and use a measuring tool to measure the width of the white square which appears on the CRT screen. Enter the width value in microns (um) into the Interline Width box.
Close & Save.
To check that the value saved correctly, please open a VEP protocol and measure the 1 degree squares.