PIRA Classification: 6A65.71
Description: A Fresnel lens inside of an overhead projector has a focal point about 1.5 feet above the glass. A thermocouple is used to probe the temperature at various points above the overhead. Also, a sheet of black paper can be made to smoke when placed at the focal point.
Special Instructions: None
Condition: Ok
Setup time: 2 minutes
Safety Issues: None