ANALYTICAL
62 A
gives you faster, more accurate
Manufacturing Control Tests The precision instrument for photo electric colorimetry. FASTER—You make routine tests in three quick steps with a single control for all adjustments.
•x
•
Uses 5, 10 or 2 0 m m . square absorption cells
•
1 0 narrow band filters 4 1 5 to 6 4 0 millimicrons
·
Direct reading microammeter
Complete $ 2 1 0 .
M O R E RELIABLE—Maximum re producibility. Different workers can obtain identical readings.
the
Leitz
INDUSTRIAL ROUYFor details, write Dept. A C 1315 E. L E I T Z , LEITZ
Inc./
SCIENTIFIC
Photrometer
3 0 4 H u d s o n St., N e w Y o r k 1 3 , Ν . Υ . INSTRUMENTS
LEICA
CAMERAS
· MICROSCOPES
AND
·
BINOCULARS
ACCESSORIES
COLLECTIVE NUMERICAL PATENT INDEX to Volumes 31-40 of
CHEMICAL ABSTRACTS Contains more than 143,000 entries: classified by coun-
•Classification by patent number is an enormous timesaver.
tries in numerical order.
• Index references give vol ume, page and location of p a t e n t a b s t r a c t in C H E M I C A L ABSTRACTS.
• Cloth bound, 182 pages, 7V2" χ 1 0 " o v e r a l l , 8 col umns o f listings per page covering all patents ab s t r a c t e d in C H E M I C A L AB STRACTS f r o m 1937-46. inclusive.
PRICE $6.50 POSTPAID S e n d orders
INSTRUMENTATION computing equipment with an over all accuracy, including relays and servos, of 1 part in 100,000. Nuclear .instrumentation is one of the few scientific activities in which these widely used devices have been borrowed from industrial or actuar ial practice. Importance
EXTRA RUGGED—Parts locked in p l a c e . . . mounted on cast alu minum base. Readings a r e always steady, regardless of vibrations.
and inquiries
to:
Special Publications Dept., American Chemical Society 1155 Sixteenth St., N.W., Washington 6, D.C.
CHEMISTRY
of Problem
Justifies
Cost
The data printer and the contin uous recorder both have individual merits and in some instances they are not competitive. Costs are com parable and one or the other may be preferable depending upon the com plexity of the data assimilation problem. In deciding whether these devices will be useful, the analyst will be governed by the "confusion ele ment" or the tediousness of the proposed measurements. He will know that primary elements or de tectors are available for converting almost any phenomenon into an equivalent electrical signal. Elec tronic circuits and packaged servomechanisms are available for con verting these signals into the pulses or shaft rotations required by the printer. The high cost involved in an elaborate installation can be justified by the importance of the problem alone, but in this connec tion it is worth noting that data as similation is one phase of research which is rarely relegated to the tech nician. Manufacturers
Instruments of the type described in this report are available from the following manufacturers: Taller & Cooper, 75 Front St., Brooklyn, Ν. Υ. ; Simplex Time Recorder Co., 377 Broadway, New York, Ν. Υ.; Roberts Numbering Machine Co., 700 Jamaica Ave., Brooklyn, Ν. Υ.; Streeter-Amet Co., 4101 North Ravenswood Ave., Chicago, 111.; In ternational Business Machines Corp., 590 Madison Ave., New York, Ν. Υ.; The Electronic Signal Co., 541 Willis Ave., Williston Park, Ν. Υ.
