The Hewlett Packard 8452A Diode-Array Spectrophotometer with Multicuvette Holder is capable of acquiring complete Visible absorbance spectra in as little as 100 msec. The key is that the grating of this instrument is fixed, and rather than moving the grating to acquire spectra, hundreds of detectors are placed at the exit of the monochromator. The HP 8452A has 512 detectors that are all integrated on a single silicon chip called a photodiode array. The diodes act as capacitors that discharge in proportion to the incident light flux. The capacitance of each diode is converted to a binary word that is input to a computer. The HP 8452A simplifies the operation of the spectrophotometer even further by using a deuterium discharge lamp for the full visible range, rather than a deuterium lamp for the tungsten incandescent lamp, as in done in most other instruments.