INSTRUMENTATION
Model E-6-15A Nobatron . . . WHEN
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accurate · dependable · economical
For more t h a n t e n y e a r s , Sorensen NOBATRONS h a v e p r o v i d e d r e g u l a t e d , l o w - v o l t a g e , h i g h current DC in t h o u s a n d s o f l a b o r a t o r y a n d i n d u s t r i a l a p p l i c a t i o n s . Their users h a v e chosen t h e m f o r their ± 0 . 2 % r e g u l a t i o n accuracy, t h e i r convenience o f use c o m p a r e d w i t h b a t t e r y i n s t a l l a tions or other sources, t h e i r d e p e n d a b i l i t y , their easy m a i n t e n a n c e . N o b a t r o n circuits usually e m p l o y o n l y three t u b e s . They a r e easily accessible f o r replacement w h e n r e q u i r e d . The characteristics listed b e l o w a r e c o n s e r v a t i v e a n d t e l l y o u w h y y o u s h o u l d specify N o b a t r o n . Models available (numbers indicate voltage & current) E-6-5A, E-6-15A, E-6-40A, E-6-100A, E-12-15, E-12-50, E-28-5, Ε-28-10, E-28-30, E-28-70, E-28-150, E-48-1S, E-l25-10, E-200-S.
E-12-5,
ELECTRICAL CHARACTERISTICS Input 95-130 VAC, 10, 50-60 cycles. 120/208, 3 0 , 4-wire w y e for the E-28-150. The E-28-70 requires 190/260, 10 power. Reg. accuracy ± 0 . 2 % against line, ± 0 . 2 % against load. Ripple Varies to 1 % RMS max. under worst conditions. Load range 1/10 to f u l l toad. Output range Adjustable ± 1 0 % ; down to 2 0 % at lesser accuracy. Recovery time 0.2 seconds on all models up to 1 KW rating, increasing to 0.5 seconds at 10 KW. Note: " A " models output either 6 or 7 volts. •Reg. U.S. Pat. Off. NOBATRON-RANGERS Your interests m a y best be served by an i n s t r u m e n t w i t h electrical characteristics s i m i l a r t o the s t a n d a r d N o b a t r o n , b u t w i t h stepless, continuously a d j u s t a b l e o u t p u t . I f so — f i n d out more a b o u t Sorensen's line o f Nobatron-RANGERS. ELECTRICAL CHARACTERISTICS Input 95-130 VAC, 1 0 , 50-60 cycles for SR30 and SR100. 190-260 VAC, 10, 50-60 cycles for the SR2. Reg. accuracy ± 0 . 2 5 % at any voltage setting. Ripple 1 % RMS max. Output: Model SR100 SR30 SR2 VDC 5-135 5-30 100-300 Amps 1-10 3-30 1-10 TUBELESS N O B A T R O N S Sorensen is a w a r e o f the a d v a n t a g e s o f tubeless circuitry, a n d m a n u f a c t u r e s a line o f tubeless supplies, a l s o . M o d e l SR2 ELECTRICAL CHARACTERISTICS ~" Model MA65 MA640 MA2850 I n p u t , VAC, 60-v 105-125,10 105-125,10 190-230,30,4-wire, wye O u t p u t , VDC 6, a d j . ± 1 0 % 4.5-7.7 a d j . 23-32 a d j . Load range 0-5 amp. 0-40 amp. 0-50 amp. Ripple 1 % max. 1 % max. 3 % max. Model Reg. accuracy b l . 0 % for any combination of line and load. MA640 Recovery time 0.2 sec. 0.15 sec. 0.5 sec. Catalogs available describing the complete line of Sorensen instruments. Write for free copies today.
SORENSEN & CO., INC., 375 FAIRFIELD A V E N U E , STAMFORD, CONNECTICUT For further information, circle number 52 A on Readers' Service Carl, page 55 A
52 A
system (Figure 2). A typical polarogram taken with this attachment is shown in Figure 1. Standard thermocouples can be used with the Recordall. In the case of Chromel-Alumel thermocouples for the range 0° to 1000° C , cold junction compensation is provided within the instrument and special chart paper is available graduated directly for this temperature range. An example of thermometric measure ments is shown in Figure 3 for the melting and freezing of a tin alloy. These results were obtained with the resistance thermometer bulb. Other primary elements and trans ducers are being developed and will be described as they become available. Of particular interest would be im pedance matching circuits for use with vacuum phototubes. Fisher reports that such developments are well under way. The existing adaptation to the glass electrode pH meter indicates that comparable cases can be handled. The flexibility and wide utility of this equipment should be very interesting to the research-minded analyst. Re corders are not scarce in analytical laboratories, but as a rule, they have been incorporated in specific-purpose instruments. Compilations A few years ago, Du Mont issued a pamphlet on transducers or primary elements, primarily those which are suitable for presenting physical infor mation to an oscilloscope. This was an extremely useful compilation for the research man. It listed characteristics, range, and limitations, and also de scribed sources of such equipment. The advantages of this compilation were described in this column at the time. A similar compilation for recording potentiometers would be most useful. We are aware that this sort of thing has been done from time to time by our good friends who build recorders, and indeed, as stated above, they are pre pared to make valuable suggestions as our problems arise. It is also true that dozens of transducers for specific prob lems are on the shelf awaiting applica tion. Nevertheless, this is a resume which is appropriate at frequent inter vals and it does no particular harm to repeat, and to bring up to date, a listing of those devices. We are one of those investigators who manage to keep many recorders on hand, of wide range and versatility, but despite this, a new problem or new approach finds us busy with the very first consideration—a transducer element to convert the phenomenon into something which we can "hook on" to the best recorder. ANALYTICAL
CHEMISTRY
