New Products
BEL-ART T H E PROVEN PLASTIC
desiccator AVAILABLE IN THREE SIZES
This proven plastic desiccator permits application of high vacuum, which is retained by a specially designed reten tion valve, located on the upper section. Extremely light but strong and easy to handle. Good chemical resistance. Per mits the use of incandescent crucibles with conventional plates. The Bel-Art Desiccator operates successfully over a wide range of temperatures, seal unaf fected by low temperatures (0° C).
The lower section is made of tough polypropylene. The flange design of fers no interference with the normal sliding of top section off bottom when opening. Groove molded into flange of bottom section holds neoprene O-ring, which provides superior seal between halves. Vacuum line connects to upper half, the lower load-carrying half is free to be moved when necessary. See your nearest laboratory supply dealer. Our NEW supplement is now available. For your FREE copy write Dept. A-1
BEL-ART PRODUCTS PEQUANNOCK, N . J. 0 7 4 4 0 Circle No. 44 on Readers' Service Card
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ANALYTICAL CHEMISTRY
Model STC-1055 Variable Tempera ture Control System is designed for both NMR and EPR/ESR applications. The system utilizes flowing dry nitro gen gas to control the thermal en vironment of a sample surrounded by the rf field of a resonance experiment. Temperature range is from —175 to + 3 0 0 °C. Not only the sample but also its immediate surroundings are subjected to the thermal influence of the flowing gas, thus reducing thermal gradients near the sample to 0.5 °C.
The desired temperature is set on the controller by means of a digital set point indicator. Deviation of the gas stream temperature, as monitored by the control thermocouple, results in a proportional change in heater power. Accurate monitoring over a wide range in ambient temperatures is ensured by electrical cold junction compensation of the control thermocouple. Ventron Instruments Corp., Magnion Division, 144 Middlesex Turnpike, Burlington, Mass. 01803 402
Lead Ion Determinations
Automatic Buret
Lead ion activity electrode, Model 92-82, measures Pb 2 + from 2 X 10 ~2M to 10~ 5 i¥—down to 0.2 ppm—in a wide variety of aqueous solutions. The body of the electrode is made of an un breakable fluorocarbon plastic which is highly resistant to chemical attack. The electrode sensing element is a liq uid ion exchanger which is extremely selective for lead ion over other com mon cations. Orion Research, Inc., 11 Blackstone St., Cambridge, Mass. 02139 403
An automatic buret with an all-Teflon (DuPont) valve body is available. No glass-to-glass seals to jam and no need for lubrication. Buret, valve, and res ervoir come apart for easy cleaning. The buret comes in two sizes, 10 ml and 25 ml, and each has its own 500-ml res ervoir. The cap that locks on the buret assembly will also take most 1-quart reagent bottles, all standard 5-pint acid bottles, and many 1-gallon polyethylene jugs of standard solutions. Fisher Sci entific Co., 312 Fisher Bldg., Pittsburgh, Pa. 15219 405
Mortar and Pestle
Pulverit 4 is fabricated from highpurity single-crystal sapphire. The unit has a capacity of 5 grams and can be used to prepare samples for trace, X-ray, and spectrum analysis, plus nu clear, solid state, ceramic, and geoscience research. Prime advantage of the Pulverit 4 is the absolute hardness and zero porosity of the grinding element surfaces. Also, sapphire provides greater abrasion resistance than any synthetic material. Geoscience Instru ments Corp., 435 E. Third St., Mount Vernon, Ν. Ύ. 10553 404
Biased Amplifier Model 1462 incorporates design con cepts that make it particularly suitable for high resolution, high count rate nu clear spectroscopy. The instrument in cludes an integral baseline restorer and a pulse pileup rejector circuit. These two features permit the experimenter to optimize resolution and performance at even the highest counting rates. Model 1462 includes a pulse stretcher, linear gate, and choice of area or peak mode detection. Canberra Industries, 50 Sil ver St., Middletown, Conn. 406
