INSTRUMENTATION 2 0 0 : 1 ratio of m a x i m u m to minimum speed.
-r-Λ 6 8 MINUTES
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Figure 4. Limonene: column charge 0.4 mg.; column temperature 176° C. Constituents unidentified
I F VISCOSITY I S O N E OF YOUR PRODUCT'S D I M E N S I O N S Brookfield 8-speed Viscometer will answer every measurement problem! W h y not invest a three-cent s t a m p a n d see w h a t we m e a n ? O u r illustrated brochure shows you how t h e Brookfield 8-speed viscometer a n d spe cialized accessories will answer every viscosity m e a s u r e m e n t problem you m a y have. You'll see how this one, easily operated, portable i n s t r u m e n t will provide precise m e a s u r e m e n t readings directly in centipoises. E v e n in applications involving extremes in viscosity, t e m p e r a t u r e or corrosion!
0.2 mm. The detector incorporates a number of baffle plates which are essen tial to reduce the effects of draughts. With high temperature columns it has been found necessary to replace the iron constantan thermocouple with one of platinum/14 per cent rhodium platinum. The theory of the detector is not yet clear, but it depends upon the heat of combustion and rate of burning of the vapour. A linear relationship has been found between peak area and weight of a hydrocarbon vapour producing the peak. The detector has a small volume, is easily constructed, and is particularly suitable for use with high temperature columns. In its present form it will easily detect down to about 4 microgrammes (Mg) of a vapour. We are happy to be informed that this device, which one might be inclined to regard as tricky or temperamental, has been developed and improved to the point where it forms the basis of an important and highly reliable industrial instrument. Through the courtesy of H. Freedman, Shandon Scientific Co., Ltd., 6 Cromwell Place, London, S.W. 7,
Complete information will be yours, too, about the Brookfield Helipath Stand. With it, it's easy to test, study and control highly-plastic materials, gels and semi-gels. It automatically lowers a Brookfield Viscom eter equipped with a special bar-type spindle through a helical path providing constant measurement of undis turbed material. Write for full information today. WORLD'S S T A N D A R D FOR VISCOSITY M E A S U R E M E N T D
Brookfield
ENGINEERING LABORATORIES INCORPORATED S T O U G H T O N 112 , M A S S A C H U S E T T S For further information, circle number 56 A on Readers' Service Card, page 75 A
56 A
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ANALYTICAL CHEMISTRY
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Figure 5. Peppermint Oil (American); column charge 1.4 mg.; column tem perature 176° C. Constituents: (1) (2) (3) terpenes; (4) menthone; (5) menthol; (6) menthyl acetate
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