CARLE INSTRUMENTS, INC


CARLE INSTRUMENTS, INC.pubs.acs.org/doi/pdf/10.1021/ac60302a755capabilities, but by the comprehensive support that backs...

1 downloads 63 Views 118KB Size

Instrumentation

operating on the input flux signal to obtain a desired function of flux output. This ability results from the multiplying ability of the Hall effect; that is, output is proportional to current times flux. Many other applications take advantage of this capability. Since the Hall probe yields a continuous output reading as long as the field is present, it is useful for driving the H axis on an X-Y plotter in field plotting and in tests using laboratory electromagnets. Other uses include field monitoring in spectrometers, beam deflection coils, cyclotron or linear accelerator magnets, and magnetic resonance measurements. Field programming and control of electromagnets have been carried out using Hall probes. Hall instruments have advantages in the study of flux transients in solenoids, motors, relays, etc., since thin probes will fit into narrow gaps in confined spaces and can feed signals directly to an oscilloscope for display and analysis of the field waveforms. Magnetic fields within solid material cannot be directly measured with a Hall probe for obvious reasons, but a proportional field value can often be indicated if a suitable air gap is available. A Hall generator positioned to sense the tangential field alongside a fluxcarrying member can read the value of surface II and is used for this purpose in B-H plotters, permeameters, and coercimetcrs. Magnetic susceptibility and saturation magnetization (a) of small samples have been measured using Hall devices. Industrial applications include the control and adjustment of field strength in the manufacture of dc motors, relays, and similar devices, and in the nondestructive testing of parts by magnetization or by eddy current methods. Noncontacting measurement of electric current is accomplished using Hall generators to sense the field around the conductor. Electric power is measured by Hall multipliers designed for use in power circuits. A host of other applications exist beyond the scope of this article, many of which have become feasible as a result of recent advances in Hall device technology. References

(1) "The Hall Effect and Its Applications," F. W. Bell Inc., Columbus, Ohio, 1962. (2) M. Epstein, L. J. Greenstein, H. M. Sachs, Proc. Nat. Electron. Conf., 15, 241 (1959). (3) A. J. Monks, U. S. Patent 3,469,092 (September 23, 1969). (4) R. J. Higgins, Rev. Sci. Instrum., 36 (11), 1536 (1965). (5) W. Viehmann, ibid., 33 (5), 537 (1962).

FOR SALE 4 5 years experience—$585 w e t h r o w in the G C . . . Free.

Chemists don't buy a gas chromatograph, they buy solutions to problems. Just how well a gas chromatograph solves problems is determined not only by the instrument's inherent capabilities, but by the comprehensive support that backs up those capabilities. The technical competence of Carle Instrument's $585 Model 8000 Basic™ Gas Chromatograph is well established. There are hundreds in use all over the w o r l d . Behind our technology is a total of 45 years of gas chromatography application experience — yours to draw on simply by picking up the phone. We pride ourselves on being shirt-sleeve chromatographers. When that phone rings, we provide solutions ranging from syringe selection to the most sophisticated multi-component gas analysis. Using this shirt-sleeve experience to carefully pick and choose, Carle offers a complete line of field-proven chromatography accessories right from stock. Columns, fittings, valves, pressure regulators. A convenient, single source for all of your Basic™ Gas Chromatograph needs, both special and routine. Write today for detailed literature on our $585 Model 8000 Basic™ Gas Chromatograph and chromatography accessories. Better yet, put in a collect call to our Vice President, Bill Butz (714) 879-9900. He'd like to hear from you.

C A R L E I N S T R U M E N T S , INC.

1141 East Ash Avenue, Fuilerton, California 92631, (714) 879-9900

CIRCLE 3 4 O N READER SERVICE CARD

ANALYTICAL CHEMISTRY, VOL. 43, NO. 7, JUNE 1971



71 A