COLEMAN
NEW PRODUCTS
Stable to 0.01% . . . Indefinitely
NEW KEITHLEY
3500V DC. SUPPLY
Refinery control lab determines nitrogen automatically on round-the-clock basis
Process gas analyzer is designed to fill the gap between crude portable instruments and the p.p.m. instru ments. Argon, nitrogen, oxygen, hy drogen, etc. are analyzed using a thermal conductivity cell to an accu racy of ± 2 % full scale. Model S - l . Thermco Instrument Corp., Laporte, Ind. 423
Using the automated Coleman Nitro gen Analyzer as basic equipment, the quality control laboratory of The Atlantic Refining Company (Phila delphia) determines nitrogen content of petroleum products down to 0.02 % nitrogen. Operated by control chemists on all three shifts, the instrument provides a complete nitrogen analysis in as little as 8 minutes. It is used for critical quality control work with gas oils, lube oil additives, greases and synthetic detergents. The instrument is fully as efficient in the control laboratory environment as it has proven under carefully-con trolled research laboratory conditions. Write for the specific method devel oped by Atlantic Refining's Product Quality Department for nitrogen de termination in refinery fluids—Cole man Technical Report AT-187.
COLEMAN COLEMAN INSTRUMENTS, INC. MAYWOOD, ILLINOIS Circle No. 127 on Readers' Service Card
The extreme stability of the Model 242 is not specified in hours. N o w over several months—you can per form extended duration measurem e n t s . C u m u l a t i v e d r i f t of t h i s regulated supply is prevented by a self-correcting feedback loop fea turing a temperature compensated zener diode reference, photo-chop per comparator and wire wound sampling resistors. 300 V to 3500 V are delivered at 25 ma, with less than 1 mv combined ripple and noise— ideal for photo tube, photo multiplier and electron multiplier applications. Other specifications contributing to the outstanding value of the Keithley 242 are shown below. • o u t p u t : 300 t o 3,500 V at 25 m a in 1 volt s t e p s — p l u s , m i n u s , or f l o a t i n g t o 4500 V • stability: 0 . 0 1 % i n d e f i n i t e l y , minute warm-up
after
30
• accuracy: = 0 . 1 % • ripple and noise: Less t h a n 1.0 m i l l i volt r m s • line r e g u l a t i o n : 0.005% for 10% c h a n g e in line v o l t a g e • load r e g u l a t i o n : 0.005% f r o m z e r o t o full l o a d • overload p r o t e c t i o n : A u t o m a t i c dis c o n n e c t if c u r r e n t e x c e e d s 27 m a • price: $850
Other Regulated DC Supplies This Dual Titrometer provides a range of - 1 6 5 0 to + 1 6 5 0 mv. and 0 - 1 4 pH units, electrometric circuit sensitivity of less than ± 2 mv. ( ± 0 . 0 2 pH), in dicating meter with full scale deflec tion of 250 mv., and grid current of ΙΟ - 1 3 amps magnitude. "Mag-Mix" stirrers provide convenient stirring control. Bulletin 615A. Precision Scientific Co., 3 7 3 7 W. Cortland St., Chicago 4 7 , III. 424
M o d e l 241, 0 1000 V, 0.05% a c c u r a c y
$800
M o d e l 240, 0-1000 V, 1.0% a c c u r a c y
5345
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K E I T H L E Y I N S T R U M E N T S 12415 Euclid A v e n u e
· C l e v e l a n d 6, Ohio
Circle No. 41 on Readers' Service Card
VOL 34, NO. 13, DECEMBER 1962
·
125 A
