Manufacturers' Literature
dards, accessories, determination of morphine and quinine from biological specimens, and such items as recent advances in phophorimetry. A bibliography is also given. American Instrument Co., Inc., 8030 Georgia Ave., Silver Spring, Md. 20910
The best is usually more expensive
Newsletter/Specific Ion Electrode Technology. The August 1969 issue, 8 pages, introduces a new electrode for potassium ion and discusses analytical techniques, electrodes in medicine, and contains abstracts from recent periodicals relating to specific ion technology. Orion Research, Inc., 11 Blackstone St., Cambridge, Mass. 02139 Analytical Advances. Vol. 2, No. 2, 16 pages, include articles on the use of the H-P 7600A chromatography system and on the Series 7602A research gas chromatographs. Hewlett-Packard, Route 41 and Starr Rd., Avondale, Pa. 19311 Instrumentation. Vol. 22, No. 2, 32 pages, concentrates on lab recorders, miniature instruments, water temperature studies, automated plant facilities, and thermocouples. Honeywell, Inc., Fort Washington, Pa. 19034 Ramalogs. Vol. 2, No. 2 & 3, 8 pages, discusses the use of interference filterneutral density chopper discs in Raman spectroscopy. Spectra and other data are given. Spex Industries, Inc., 3880 Park Ave., Metuchen, N. J. 08840 Research Notes. This July 1969 issue, 12 pages, contains articles on liquid chromatography detectors, radiochromatography scanning, pyrolysis of paint, ghost peaks, and an ultrastable liquid phase, among others. Varian Aerograph, 3700 Mitchell Dr., Walnut Creek, Calif. 94598 Spex Speaker. Vol. XIV, No. 2, 8 pages, contains Part II of an article by S. P. S. Porto on light scattering with laser sources. Spex Industries, Inc., Box 798, Metuchen, N. J. 08840 Current Laboratory Practice. The July issue's feature article is on the quantitative elution of microgram quantities of steroids from silica gel layers. Gelman Instrument Co., 600 South Wagner Rd., Ann Arbor, Mich. 48106 Data Sheet. Vol. 1, No. 2, 4 pages, describes biwall columns used in preparative scale chromatography. Six case studies are given. Nester/Faust Mfg. Corp., 2401 Ogleto\vn Rd., Newark, Del. 19711
...but not these new Keithley Lock-in Amplifiers Over the years, Keithley has developed a reputation as a leader in simplifying DC measurements. Now we have another advance . . . the Keithley 82 and 83 Lock-in Amplifier Systems which use the wide band approach to simplify AC, as well. If you're trying to isolate low level signals lost in noise, look at what we offer: • • • • •
sensitivity of better than 500 picovolts center frequencies from 1 Hz to 1 MHz resolution to 0.01% 0.005%/°C zero stability, and a building block approach where you buy only what you need Either system offers unparalled advantages in terms of quick set-up, easy operation and versatility of performance. To make your lock-in amplifier money talk, talk to Keithley. About the System 82 for highly sensitive and demanding applications (for only $1895). Or the System 83 for less stringent uses (just $1595). If you don't need the complete system, buy only the Phase Sensitive Detector, Low Noise Amplifier or Phase Shifter. For full technical details or help with a specific problem, call your experienced Keithley Sales Engineer. Or contact Keithley Instruments, Inc., 28775 Aurora Road, Cleveland, Ohio 44139.
K K E I T H L E Y Circle No. 40 on Readers' Service Card
VOL. 41, NO. 12, OCTOBER 1969 • 149 A
