INSTRUMENTATION indebted to our more progressive in strument manufacturers who are con tributing in this way to the collection of definitive information on the newer methods of analysis. The delineation and recording of data at extremely high speed continue to occupy the attention of all scientists. The chemist has countless problems in volving the same requirements and to a large degree, kinetic studies have always been limited by the available means for following the process. While oscillographic methods have always been in the forefront, direct photo graphic methods have the distinct advantage of yielding a large amount of information, much of which can be examined at leisure, after the event.
N-M-R Solves Chemical Puzzles . . . No instrument offers greater advantages for advanced study of chemical systems than Varian's V-4300B High Resolution n-m-r (nuclear magnetic resonance) Spectrometer. This "nuclear detective" is now being used by scientists in many well known universities and research centers for determining molecular structures, analyzing functional groups and monitoring chemical reactions. In all these applications it provides non-destructive observation of undisturbed chemical systems, requires a minimum of sample preparation time. Here are some advanced features of the V-4300B High Resolution n-m-r • • •
Spectrometer:
Exclusive Varian sample spinner permits fine separation of closely spaced resonances. Complete Varian magnet system available to provide unsurpassed field stability and homogeneity. New console mounting puts all controls within easy reach of operator.
THIS IS N-M-R AT WORK JH1K5RUM
OF UNOUJÇ ACID
DATA
Sample: 25% Linoleic acid in CCU Volume: 0.03 ce. i
ofsuchagroupml.noleicacKlisrewa.ea
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peak Β in the n-m-r spertrum Peatt , CH> correspond respectively ' ° ^ X „ d , aliphatic CHS groups adjacent to ont)» ο»· £ ™ * ° ° s while far off groups, and the ter mina m t h y u r » Ρ resonariCe to the left of the trace, the ca'ooxy, ρ ^ ffom
Signal Observed: H
Frequency: 30 mc. Field: 7050 gauss SweepRate:1.5milligauss/sec,
would · Ρ Ρ « ' · ^ Μ ί d hnolenic acids, and S r a S 0 a U n t n c h e S m i c a l " n the paint industry. F
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+2 FOR C O M P L E T E
INFORMATION...
On the Varian V-4300B High Resolution n-m-r Spectrometer and associated Magnef System, write the Special Products Division for:
THE MARK OF LEADERSHIP
VA
V A R I A N P A L O
A L T O
4,
_. n _ . . • n-m-r Table
associates C A L I F O R N I A
MICROWAV Ε Τ U BES — SPECI AL PRODUCTS. For further information, circle number 36 A on Readers' Service Card, page 39 A
36 A
Rotating Mirror Frame Camera The famous million frame per second camera has been in use for 5 years at the Los Alamos Scientific Laboratory, primarily for the investigation of ex plosive and related phenomena. It has been described in considerable de tail recently by Berlyn Brixner [/. Opt. Soc. Amer., 45, 876(1955)]. The design and construction of this rotating mirror frame camera are described. Twenty-five consecutive pictures 20 mm. in diameter can be obtained on a strip of 35-mm. film. A resolution of at least 20 lines per mm. is obtained on a moderately fast film. Since the "seeing" time of the camera amounts to only 12% of its cycle of operation, accurate synchronization and the use of explosive initiators are required. A number of photoelectric trigger and pulse generating circuits are available for the rapid firing of electric detonators and synchronization within 2 micro seconds. The camera employs a two-faced rotating mirror driven at 5000 revolu tions per second and a refocused re volving light beam. There are 25 fixed framing lenses in a 90° quadrant or 100 per circle. To avoid multiple exposures a very fast shutter is re quired. The shutter is made by det onating a primacord explosive fuse at a point near the window of the camera. The explosion of the primacord pro duces an opaque cone-shaped shock wave enclosing a smoke cloud. This opacity persists until the smoke is dis sipated by convection or by shock waves from the phenomenon under investiga tion. Other cameras of this kind have been made with picture sizes ranging from 6 to 35 mm. and number of frames from 48 to 170 and with frame frequencies from 5 Χ 104 to 1.5 X 10' per second. Synchronization difficulties can be ex pected to increase in proportion to speed and number of desired frames. ANALYTICAL
CHEMISTRY
