N e w Products
Check Your Temperature 54 Ways Try a hypodermic needle, metal disc, glass probe, stainless steel tube with pipe fitting, or any of the more than 50 YSI thermistor probes. Add a YSI Telethermometer and read temperature directly from — 8 0 ° t o + 1 5 0 ° C . (We also have instruments for accurately controlling temperature.) Write for our catalog and learn the advantages of YSI thermistor probes and instruments.
M o d e l U A - 4 u v c o l u m n d e n s i t o m e t e r feat u r e s h i g h - s e n s i t i v i t y a b s o r b a n c e recording, built-in calibration standards, a n d f l o w cells w h i c h s e l d o m need degassing. M i c r o v o l u m e cells are also available f o r s m a l l c o l u m n s . Five single- or d u a l - b e a m o p t i c a l units ope r a t i n g a t 2 5 4 n m , 2 8 0 n m , or o t h e r uv or ir w a v e l e n g t h s can be s e l e c t e d . The u n i t is available w i t h e i t h e r a rec o r d e r or a m e t e r f o r use w i t h e x t e r n a l recorder. Accessories can a d a p t t h e UA-4 f o r s c a n n i n g c e n t r i f u g e d d e n s i t y gradients and electrophoresis columns. A Model 9 5 0 electronic integrator (not s h o w n ) is a v a i l a b l e as a s e p a r a t e u n i t . The i n t e g r a t o r , also, can be used w i t h o t h e r i n s t r u m e n t s w h i c h have an analog o u t p u t . $ 8 4 5 t o $ 1 4 9 5 w i t h o u t integrator. Instrumentation Specialties Co. 4 0 2 - 4 3 4 - 0 2 3 1 453 Dual d u t y f r e e z e r / i n c u b a t o r o p e r a t e s a t — 2 0 ° C f o r s t o r a g e o r can i n c u b a t e from 2° to 50°C. M o d e l 3 5 2 7 0 1 permits temperature control within ±0.25°C. Five shelves p r o v i d e 2 4 0 0 i n . 2 of s h e l f a r e a ; 15 ft 3 of clear l o a d space. $ 5 9 5 t o $ 6 9 5 . Hotpack Corp. 215-333-1700 454
YELLOW SPRINGS INSTRUMENT CO. YELLOW SPRINGS, OHIO 45387 Circle No. 195 on Readers' Service Card
Series 2 8 0 s e r v o g r a p h i c r e c o r d e r s use true potentiometric null balance system; M o d e l 2 8 0 1 is a s i n g l e pen w i t h f u l l 1 0 - i n . c h a r t paper; M o d e l 2 8 0 2 is d u a l pen w i t h each c h a n n e l , literally, an i n d e p e n d e n t recorder. 2 8 0 1 recorder, $445 to $650; 2802 two-channel, $695 to $950. L a b o r a t o r y Data C o n t r o l . 202-226-0759 455
BIORAD stocks DOWEX® ion exchange resins, anion and cation, in 44 types and bead sizes.
For immediate shipment! Need we say more? Only that BIO-RAD's AG© resins—the research standard of excellence— are also available for those applications requiring the highest chemical purity. For details on DOWEX and AG, send for our new complete catalog and price list.
-BIO-RAD Laboratories 32nd & Griffin Ave. Richmond, Cal. 94804 (415)234-4130 220 Maple Ave. RockvHIe Centre, NY 11570 (516) 764-2575 Circle No. 29 on Readers' Service Card
ANALYTICAL CHEMISTRY, VOL. 43, NO. 4, APRIL 1971
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