This specirum of mdene and indone — camphor — cydohexanon-y was recorded \n 16 minutes 'hro'jgh use of Model 421's long-wavelength grating interchange.

NEW MODEL 421 INTERCHANGE GIVES TOP RESOLUTION AT LONGER WAVELENGTHS

Perkin-Elmer's Mode l 421 Grat ing Spectro­photometer is a l ready known for its out­s t a n d i n g p e r f o r m a n c e o v e r the basic

infrared spectrum. N o w , a new interchange extends this performance into longer wave­lengths. You can have both the basic 4000-550 wavenumber range and the new 2000-250 wavenumber range by a simple switch of interchange assemblies that takes less than f ive minuses, requires no warm-up t ime or opt ical adjustment.

Both interchanges give you true grating r e s o l u t i o n — p lus the M o d e l 421's t o p -efficiency f /4 .5 opt ical system that scans

faster and handles samples smaller than any comparable instrument. An integral automatic speed suppression system guar­antees accurate spectra in minimum t ime, add ing to your work ing eff iciency.

Get the whole story on what the Mode l 421—and its accessories —can do in your own appl icat ions. Wr i te today for the new Mode l 421 brochure. The address: Instru­ment Division, Perkin-Elmer Corporat ion,

751 Main Avenue, Norwa lk , Connecticut.

PERKIN ELMER