Introducing NATIΟΝΑL TRADE-MARK
high-density platform discCatalog No. L-4081
s p e c i a l l y d e s i g n e d for testing of light oils a n d other materials where minimum penetration of t h e s a m p l e into t h e e l e c t r o d e is d e s i r e d .
This newest member of the "National" electrode family is made of a highdensity graphite that gives the pene tration resistance often desired in test ing liquids such as light hydrocarbons. It supplements Platform Disc L-4078 — now widely used for analysis of powders, heavy oils and non-penetrat ing solutions on a horizontally revolv ing platform. National Carbon Company also sup plies discs for rotation in the vertical plane: Disc L-4072 and Disc L-4075.
Disc L-4072 — Used when large volume of sample must be delivered to point of excitation. Disc L-4075 — Used when a large volume of sample is not required at point of excitation. All "National" spectroscopic electrodes and powders — materials and finished product — are tested by the cathodelayer method, most sensitive known in emission spectroscopy. There is no measurable ash in these products.
N o w ! 4 0 s t a n d a r d p r e - f o r m e d s h a p e s , including 4 d i s c s . . . d e s i g n e d to m e e t e v e r y s p e c t r o s c o p i c n e e d . The term "National" is a registered trade-mark of Union Carbide and Carbon Corporation N A T I O N A L C A R B O N C O M P A N Y · A Division of Union Carbide and Carbon Corporation · 3 0 East 4 2 n d Street, New York 17, N.Y. SALES OFFICES: Atlanta, Chicago, Dallas, Kansas City, Los Angeles, New York, Pittsburgh, San Francisco · IN CANADA: Union Carbide Canada Limited, Toronto For further information, circle number 28 A on Readers' Service Card, page 75 A 28 A
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ANALYTICAL CHEMISTRY
