COMMON PROBLEMS IN CHROMATOGRAPHY # 8
Connecting Glass Columns Without Leaks or Breakage
Atomic absorption spectrophotometers from IL are superior in many ways : built-in video display, dual-element capability, greater freedom from interferences, high sensitivity, excellent applications and service support.
Enuf!
Isn't it frustrating when you have just finished installing a glass column, but it leaks? Then when you t r y to tighten the nuts, the column breaks. Now you must start over again, but first you have to repair, or replace, the column. All of this because you overtightened the fittings. But how are you to know when the fitting is tight enough? A variety of ferrules are available to make this connection, and each type may require a different degree of tightness to ensure against leaks. First, install the nut finger tight to ensure that the threads are properly matched (stripped threads also result in expensive and time consuming repairs), and then use a wrench, if necessary, to obtain proper tightness. Caution: Tightening nuts with a wrench should be just sufficient to prevent leaks — and no more! The various ferrules differ in degrees of hardness, so when you change from one type to another you should experiment with plain tubing to find the tightness required before installing a column. But there is an easier way. Use our Glasrench which will disengage when the nut has been sufficiently tightened. (We offer Glasrenches which are preset for specif ic ferrules.) Or t r y our graphite ferrule, Supeltex M-4, which requires only finger tightening t o provide a good seal. Seven different types of ferrules, the Glasrench, and tips on use, etc., are described in our FREE Bulletin 7 4 1 . If you don't already have a copy, w h y not request one now? While you're waiting for i t , t r y a package of the finger-tighten-only Supeltex M-4. 2-2492
Supeltex M-4, 1/4", pack of 10
|2-2901
Glasrench Model A for 1/4" Supeltex M-1 and Supeltex M-2
12-2903
Glasrench Model C, for 1/4" Supeltex M-4 and Supeltex M-2A
$26
$60
$60
IL's n e w Plasma-100 sequential emission spectrometer determines u p to 32 elements in t w o minutes. It is an easily operated and versatile unit, compact in size and modest in cost. For more information, please call 617-658-5125 or write: Instrumentation Laboratory Inc., Analytical Instrument Division, 56 Jonspin Road, Wilmington, MA 01887. "The leader in atomic spectroscopy has a new name..."
«A!
Instrumentation Laboratory CIRCLE 105 ON READER SERVICE CARD
quantitative vacuum measurements with Datametrics Electronic Manometer and Barocel Sensor In the range of 10 5 to 5000 Torr. with 10 to 100 times better accuracy than McLeod, Ionization or Thermal Conductivity Gages. — And calibration accuracy independent of gas composition. Applications include measurements of vapor pressure, cryogenic temperature, flow, surface area and adsorption, mass spectroscopy, fluid mechanics, leak testing, gas kinetics, freeze drying, vacuum metallurgy, and sputtering.
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Continuous direct reading.
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High level dc output signal.
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Sensors bakeable to 450°C.
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Multi-Station inputs.
Datametrics offers a broad line of vacuum and pressure measurement systems for critical applications.
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Compatible with UF6, HF, F2
•· Digital outputs.
For further information, contact:
SUPELCO, INC. SUPELCO PARK. BELLEFONTE. PA 16823 TELE: 814 359-2732/TWX : 510-670-3600 CIRCLE 192 ON READER SERVICE CARD
datametrics
Datametrics, Inc. 340 Fordham Road, Wilmington, Mass. 01887 Phone 617-658-5410-TWX-710-347-7672
CIRCLE 54 ON READER SERVICE CARD ANALYTICAL CHEMISTRY, VOL. 53, NO. 3, MARCH 1981 · 449 A
