spectrophotometers

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HITACΗΙ 100

the photometric energy savers from Thomas

their concave grating ensures more signal, less noise. In the perfect spectrophotometer, only the sample takes energy from the light beam. There are no lenses and mirrors to fog, and no long light path to be affected by particle scattering. These can dissipate up to 60% of source-produced energy. In the new Hitachi 100 Series Spectrophotometers, there is not a single lens, there is only one mirror, and the light path is very short indeed. From the energy-saving standpoint, these instruments are more nearly perfect than any spectrophotometers commercially offered to date.

To focus the light beam without multiple mirrors and lenses, the Hitachi 100 Series instruments employ a concave, instead of planar, diffraction grating. The curvature of the surface on which the grating is ruled does the focusing as the monochromatic beam is produced. Concave gratings are not new. Their advantages have been realized for many years. What is new is the Hitachi-developed technology which now allows such engine-ruled gratings to be-mass-produced, to be put into spectrophotometers which sell at prices being paid for piano-ruled grating instruments.

The big advantage is in the improved strength you'll find in the photosensor signal, before amplification. The sample can take more energy from the stronger beam, leaving more than enough for the photosensor to work with. Less amplification of the signal is required, and you can be more confident that you're reading Absorbance instead of noise. In the digital models you can be confident all the way up to A = 3.

Resolution is also improved since narrower slits can be used with the higher energy focused on them. And, of course, since there are fewer optical components, there is less operational maintenance. And the shorter light path permits more compact instrument design. We at Thomas are confidently enthusiastic about this new Hitachi 100 Series. Let us give you details on the concave grating and their other design features. Arthur H. Thomas Company, Vine Street at Third, Philadelphia, PA 19106.

A R T H U R H .

THOMAS C O M P A N Y

CIRCLE 214 ON READER SERVICE CARD

ANALYTICAL CHEMISTRY, VOL. 47, NO. 14, DECEMBER 1975 · 1235 A