Feb 2002PerkinElmer InstrumentsRequest Info
The model 198A dual-beam light chopper from PerkinElmer Instruments Signal Recovery is suitable for pump-probe and optical ratiometric experiments. It uses a quartz crystal oscillator as its primary frequency standard for accuracy and stability in beam modulation frequency. The device also can be used as a single beam chopper to generate modulation frequencies from 55 to 1500 Hz by selecting the appropriate aperture. The light chopper's electrical reference signal can drive the reference channel of a lock-in amplifier or other signal recovery instruments.