Description

Bentham 218M Optical chopper controller - modular control electronics. For ise in 217 / 417 bin or equivalent. Simple Type: Optical Chopper In measurement scenarios where the optical signal to be measured may be confounded with a background optical signal, either from ambient lighting, or, in the infrared, heat (or infrared radiation) emitted by instrumentation and the background, a means of discrimination between the two is required. This is achieved by modulating the desired optical signal on a known carrier wave by an optical chopper. The 218M optical chopper consists of a modular control unit coupled by a 2m long lead to the chopping head. Four, easily interchangeable, chopping discs are provided, which allow chopping frequencies in the range of 0.5Hz to 4kHz. A variable aperture 2-slot disc and higher frequency discs are also available. The 218M provides a square wave reference output suitable for use with lock-in amplifiers. The 218M is a single-width module, housed within the 417/T mother unit. Download the datasheet (PDF)