An instrument is described for the simultaneous measurement of circular dichroism at all wavelengths in a limited spectral range. A polychromator and a chargehyphen;coupled device (CCD), serving as multichannel sensor, are arranged behind the sample cell, which is located close to the entrance slit, in contrast to the arrangement of a monochromator before the cell and using a photomultiplier as radiation detector, as usual until now. The CCD with lowhyphen;noise electronics is driven by the system clock of a microprocessing unit controlled by a quartz oscillator and works fully synchronously with modulation and acquisition cycles. This leads to a high suppression of noise and systematic deviations. An electrohyphen;optic modulator with approximately rectangular excitation voltage is used. Partial CD spectra over the range of 80 nm each down to 200 nm have been recorded. The detection of a smaller amount of substance is possible than with other modern commercial instruments such as a JASCO Jhyphen;600, with the same signalhyphen;tohyphen;noise ratio.
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