INSTRUMENTATION by Ralph H.
Instruments to Study "Sputnik" and N e w Sensitive Pressure Sensing Device Described
D
ATELINE—0.0384 A. S. (Anno Sputnik). T h e launching of t h e world's first artificial satellite is a landmark in the history of science. T h e Russian scientists a r e t o be congratulated for this phenomenal feat. As everyone expected, t h e accomplishment was marred b y loud a n d offensive noises from t h e Kremlin a n d every political and military advantage a n d t h r e a t a r e being squeezed o u t of t h e successful effort. T h e event comes only a few centuries after Galileo, Brache, Copernicus, a n d Kepler. These giants could only observe, calculate, a n d predict, a n d even their speculations invited t h e rack or t h e s t a k e . Our leaders need fear only congressional investigations and the wrath of the uninformed. Compared with our stately scientific journals, t h e daily press is way ahead of us. T h e Gallup Poll lias finished a survey of opinion a b o u t Sputnik a n d comes t o t h e conclusion t h a t t h e average opinion is best expressed b y a Peoria housewife! Such a r e t h e wonders of statistical analysis t h a t one m a y soon expect t h e longshoremen's estimates of the merits of q u a n t u m mechanics. M a n y d a r k and sinister meanings were read into t h e i n t e r m i t t e n t beep, beep of S p u t n i k — t h a t t h e Russians were using a secret code. W h a t did t h e y expect t o hear—Elvis Presley or t h e Song of t h e Volga B o a t m a n ? I t seems fairly certain t h a t t e m p e r a t u r e a n d t h e impact of meteoritie fragments were being telemetered. T h e Russians have a d m i t t e d t h a t our own satellite will furnish much more information. Some fascinating instrumental methods h a v e been invoked for getting information from the little "fellow-traveller." F r o m t h e Hewlett-Packard Journal (supplement t o Vol. 9) we reproduce some recordings m a d e b y D r . Peterson and staff of t h e Stanford Research I n s t i t u t e . T h e record shown in Figure 1 represents a measurement of the Dôppler shift in t h e 40-megacycle transmission from Sputnik as it passed over t h e western United States o n October 10. T h e record covers some 6 minutes, during which time t h e signal happened to be " o n " continuously rather t h a n keyed. T h e recorded change in frequency after t h e signal level increased above t h e noise level is t h e Dôppler shift
Müller
in t h e received signal. T h e detailed knowledge of this shift, provided b y the counter-recorder system, enables information t o be calculated a b o u t t h e minimum slant range of t h e satellite with respect t o t h e receiving point as well as t h e velocity. T h e measurement was made with t h e equipment shown in Figure 2. T h e r-f signal was applied to a receiver with a crystal-controlled local oscillator. T h e i-f o u t p u t of t h e receiver a t about 0.5 megacycle was applied t o a HewlettPackard Model 523B 1-megacycle frequency counter, which in t u r n operated a Hewlett-Packard Model 560A digital recorder. This instrument both prints counter readings in digital form on paper tape a t high speed a n d provides a n analog o u t p u t for operating a recorder. Although a 1-second gate would give 10 times higher resolution if the signal could be relied upon in advance t o be continuous, t h e counter was operated a t a 0.1-sccond gate in the recording of Figure 1 t o ensure t h a t readings would be obtained whenever the signal was " o n " and not keyed. T h e digital recorder was operated so t h a t its analog o u t p u t was proportional
to t h e final two digits of t h e measured frequency. T h e full scale value of the record is t h u s equal t o 100 cycles per 0.1 second or 1 kc. T h e resolution of the record then becomes about 10 cycles (0.5 of a minor chart division) in 40 megacycles or 0.25 p.p.m. These and hundreds of other valuable measurements will, n o doubt, appear in our scientific journals. With their unique advantage a n d advance knowledge of t h e launching of Sputnik, t h e Russians were in a better position t o begin precise measurements. T h e imp o r t a n t question is whether they will contribute their vast a m o u n t of d a t a for t h e benefit of t h e International Geophysical Year or will continue t o wield it as a diplomatic and military blackjack. W h e n one filters off t h e sludge of political wrangling a n d recrimination precipitated b y this event, a few simple lessons emerge. I t seems to us t h a t there has been a n interminable and foolish confusion about t h e respective functions of science and technology. In technology we have demolished t h e ivory tower, installed t h e " t e a m , " and blandlv assumed t h a t this is also t h e ENTER NG RANGE
Figure 1. Doppler shift in transmission from Sputnik PRINTED TAPE
RECEIVER XTAL L.O.
-hpMODEL 5 2 3 Β COUNTER
-hpMODEL 5 6 0 A DIGITAL RECORDER
STRIP RECORDER
Figure 2 .
Equipment arrangement used to make record in Figure 1 VOL. 29, NO. 12, DECEMBER 1957 ·
61 A
SERVALL
SUPERSPEED REFRIGERATED CENTRIFUGE
®
16,000 rpm—32,700 χ G for Continuous as well as Batch Operations Continuous Flow adaptation now designed into the SEHVALL Superspeed Kefrigerated Centrifuge, brings time- and trouble-saving versatility to low-temperature centrifugation. By use of the SERVALL "SzentGyorgyi—Blum" Continuous Flow Attach ment, large volumes of sample may be centrifuged at a flow rate of up to 200 ml per minute without the laborious process of doing the job "a rotor-full at a time." Sediment is collected in one, two, four, or eight tubes, while supernatant is drained off as it is clarified. Temperatures of — 0°C. may be established, and held within ± 1 ° C . In addition to the SS-1 rotor with Continuous Flow adaptation, ten versatile rotors for batch work may be used in the stainless steel evap orating chamber. The largest of these has a maximum operating capacity of 1,770 ml.— Wide speed range—dual automatic controls — exclusive Self-Centering Assembly — still the lowest-priced Refrigerated Centrifuge in the Superspeed Range. Write for Bulletin AC-121R
Ivan Sorvall, Inc. NORWALK
·
DESIGNERS, MANUFACTURERS A N D DISTRIBUTORS OF "SEKVALL" tABORATORY INSTRUMENTS
CONNECTICUT
Since 1943 the World's largest manufacturer of Superspeed Centrifuges. For further information, circle number 62 A-1 on Readers' Service Card, page 83 A
NOW . . . an automatic, recording CHROMATOGRAPHIC REFRACTOMETER
that cuts research work
up to 7 5 % No longer is it necessary for you to perform all the time-consuming work associated with chromatographic analysis. This differential refractometer does all the work — reliably — accurately. Simply start the test, and the analysis is made automatically — unattended. The final product . . . an accurate, permanent recording of the results . . . a record you can examine immediately or file for future use. Operation is so simple that even your most inexperienced personnel can perform critical analyses with ease. What's more, where great differentials are encountered the exclusive Phoenix range-extension system permits set ting the indicator on scale without the an noyance of changing cells . . . without upsetting the zero calibration . . . and without loss of sensitivity or accuracy. A single dial adjust ment is all that's required. SEND FOR BULLETIN R-1000. No obligation. For your convenience, just attach this ad to your letterhead — or write: "* PHOENIX PRECISION INSTRUMENT CO. 3805 N. 5th STREET, PHILADELPHIA 40, PA.
PPI
Far further information, circle number 62 A-2 on Readers' Service Card, page 83 A 62
A
·
ANALYTICAL CHEMISTRY
INSTRUMENTATION proper atmosphere in which to conduct pure science. In technology, the team works beautifully, and despite fumbles and excessive whistle-blowing by the referee the technique pays off. Any budget director can prove this, and over-all planning and policy are de signed to keep things that way. When the same administrative and managerial setup presides over a purely scientific venture, the problem had better be simple and well defined, for there is grave danger that there will be more planning than work. One likes to picture a research committee, well armed with progress reports, deciding in solemn conclave that Ε = mc!. Herr Albert would have fainted at the suggestion. An alarming amount of the direction, subsidy, grants, and other fundamental aspects of scientific research hinge upon the decisions of people who have not worked in a laboratory for 20 years. Perhaps we should heed the remarks of Louis Pasteur. To two of his critics at the Sorbonne he once said, "You Monsieur, are unfamiliar with the microscope," and to the other, "And you, Monsieur, have been away from the laboratory entirely too long." There is ample evidence that the Russians have established an intellectual aristocracy. Their ballerinas, compos ers, scientists, and engineers are showered with money, facilities, and honors. That this is done at the expense of millions of others who trudge the dull and depressing treadmill of a drab existence is something which no American would tolerate. Never theless, the sober opinion of our best scientists indicates that there are several lessons which we can learn from this and which can be incorporated into our more pleasant way of life. As VannevarBush has said, "Every promis ing Russian boy is given all the education he can absorb. If he flunks, they put him in the army. In America, we put him in the army anyway." And he adds, "In our country a professor earns 2'/ 2 times as much as a laborer. In Russia he earns 8 times as much." All shrieks from the market place notwithstanding, there is nothing wrong with American science, as the Nobel Awards for the last four decades prove. It functions as brilliantly as subsidy, encouragement, and public favor permit. If we are terrified by events and by progress, the solution is very simple. It happens that we possess a very typical and blunt American expression for the remedy—"Put up—or shut up." A N e w Pressure-Sensing Device
We have made preliminary measure ments on a new pressure-sensitive
INSTRUMENTATION
Cary Applied Physics At R i k e r
instrument abstracts
Corporation/Pasadena/California
Laboratories
Cary Model 14 Spectrophotometer leads to discovery of new alkaloid in Rauwolfia series C. Howard Stimmel, Analytical Chemist at Riker Laboratories, says: "With the Cary Model 14 we detected structure in the spectra of crude Reserpine samples which was not revealed with our manual spectrophotometer. Further research led
to the discovery of Canescine, a previously unidentified member of the Rauwolfia series. Differing only slightly from Reserpine, Canescine has notable therapeutic properties of its own."
Investigation of unusual features in crude Reserpine absorption spectra obtained by Riker Laboratories with the Cary Model 14 led to the discovery of the important new alkaloid Canescine (left), a relative of Reserpine (right).
Riker chemists particularly appreciate the speed and accuracy of the Model 14, according to Stimmel. He says: "Our reasons for buying the Cary Model 14 were two-fold. One, the automatic scanning feature enables us to get more spectra in a given time; and two, we get more information from the spectra because of the instrument's greater inherent accuracy. Our laboratories are using the
Riker Laboratories, an ethical pharmaceutical specialties house with main offices in Los Angeles, California, is primarily engaged in producing hypotensive agents, including alkaloids in pure and mixed form.
Model 14 eight hours per day, five days per week, for both production control and research. Since purchasing the Model 14, we have been able to quadruple our output of spectra." "Before," Stimmel continues, "we were selective as to what we analyzed because of time limitations. Our research department now sends through anything they are even vaguely interested in analyzing. We feel the performance of the Cary Model 14 justifies our reading significance into every 'wiggle* of the spectra." Resolving power of the Cary Model 14 is better than 1A in most of the ultra-, violet visible region and better than 3Â in the near-infrared. Stray light is entirely negligible for most applications — less than 0.001% between 2100A and 1.8 microns, and less than 0 . 1 % at 1 860Â and 2.6 microns. Wavelength scale of the Model 14 is linear, and accurate to better than 4Â throughout most of its^ range: reproducibility is better than 0.5A. Why don't you consider the advantages of the Model 14's greater resolving p o w e r a n d s p e e d ? W r i t e t o Applied Physics Corporation, 362 W. Colorado Street, Pasadena, Calif., for bulletinA5-127.
Far further information, circle number 64 A on Readers' Service Card, nage 83 A
64 A
·
ANALYTICAL CHEMISTRY
device, the Celab cell, manufactured by the Clark Electronic Laboratories, Box 165, Palm Springs, Calif. The manufacturer describes these cells as follows: "The basic cells are made of metal, one side of which is inlaid with a tablet of Celab pressuresensitive plastic, a hard elastrometric medium, which changes its resistance when subjected to pressure or strain. The wide resistance change is unusual and cells may be produced with almost any final resistance desired, determined by the controlled heat-treating process incurred during manufacture. For instance, Catalog item No. 46 has a resistance change of over 200 million ohms with a small force differential in a cell no larger than a pea, and weighing 0.5 gram. Celab cells, materials, contactors, relays, amplifiers, sine wave pressure inverters, transducers, and medical instruments are covered by numerous patent applications." These cells seem to hold great promise for a variety of applications. Our examination showed that the "plastic" material more nearly resembles compressed cupric oxide; a light brushing with the finger removes a brownish dust. A small brass disk is supplied as a collector and this most certainly cannot furnish a reproducible contact with the rough surface of the pressuresensitive material. It would seem that a metal film would have to be deposited in vacuo and electrical contact made with it. We found the resistance to decrease in reciprocal fashion with applied pressure (or weight loading). As might be expected from this behavior, if the load cell is connected to a source of constant potential, then the current through it is directly proportional to load, within limits. At present we can say nothing about reproducibility, lag, or drift because we did not pursue the important point of adequate contact. Some 40 varieties of cells and ranges arc available in sensitivities of grams to 15,000 p.s.i. Special devices, using these cells, include high pressure load cells, mercury pressure transducers, stud-mounted pressure contactors, and vacuum cell. Presumably in these finished products, the contact problem has been solved. In addition, pressuresensitive powder can be obtained with an accompanying vehicle for painting it on surface. The manufacturer states that one application of these powders is the Celab cardiac catheter, an instrument for taking blood pressure inside the human heart. Resistances range from 30 ohms to 200 megohms; the former are adaptable to simple electrical instrumentation and the latter to vacuum tube and thyratron circuitry.
