ID Scanner is an identification scanner machine.
The scanner has a computer which stored handprints of United States Air Force personnel stationed at the SGC and in its registry. The scanner uses a laser to read of your hand to see if it's the right person. If it's the right person to hand imprint scanner reads green and the person pass. If the person's hand print is not in the registry scanner illuminates red and the person must not pass.
In 1998 in Nasyans driven to SGC transported to Gemmond to their new home. Ashrak Edrekh who had taken a soldier's uniform to get through the scanner but found that he was not a member of the United States Air Force and he used his Hara'kesh at the guard that dropped past him and entered the base. (SG1: "In the Line of Duty")