Edmund Optics    Barrington, NJ 08007
Jul 26, 2002 Variable frequency Optical Chopper utilizes Dual Phase Lock-In Amplifier to allow greater offset before saturation of gains settings. Blades are 102 mm diameter, chemically blacked, photo-etched discs that allow for operation frequency range of 5 Hz to 20 kHz. They come in 2, 5, 10, 30, and 200 slots. LED display provides direct read-out of chopping frequency, which is set by adjusting 10-turn dial or by applying and external, BNC control input.