NEW PRODUCTS FOR ANALYSTS Equipment, Apparatuss, Instruments, Reagents,Materials Gas Density Balance
A gas density balance has been added to the line of advanced instruments manufactured by Arnold O. Beckman, Inc. The instrument measures the density of a sample gas by a null balance principle. A small dumbbell is supported on a horizontal quartz fiber. One ball of the dumbbell is punctured so that it will not experience buoyancy effects. The other ball tends to rise or dip as the density of the gas increases or decreases. Thus, the dumbbell creates a rotational force about the quartz fiber as it responds to density changes. The magnitude of this force is proportional to the density of the sample gas. The dumbbell is metal coated to make it conductive and is held in place by an electrostatic force established with adjacent electrodes which are held at a fixed potential. When the dumbbell rotates, it is restored to its null position by applying the proper electrostatic
potential to its surface. The magnitude of the balancing potential necessary is proportional to the density of the sample. The balancing potential is used to operate a meter mounted on the door of the balance. A 9 5 % response is obtained in less than 1 minute. Sensitivity is 0.5% of full scale; accuracy is 0.5% of full scale. Ranges of 0.100 total span relative to air anywhere from 0 to 2.000 are available. Continuous samples or samples as small as 10 cc. may be measured. 1 Germanium and Silicon Lenses
Custom-designed germanium and silicon lenses may now be obtained from Baird Assoc, Inc., for use in infrared optics. Because of their high refractive indices, these single elements have appreciably less aberration than glass lenses of equal power. Germanium is transparent beyond 1.8 microns with a
50% reflection loss when uncoated; silicon is transparent beyond 1.1 microns with a corresponding 4 5 % reflection loss. The lenses may be antireflectioncoated to provide transmittance of over 90% for the spectral region of interest. 2 Combination Clinical Centrifuge
A portable combination clinical centrifuge marketed by Phillips-Drucker gives up to 11,000 r.p.m., a.c. The centrifuge features a Micro-Hematocrit head with 24 numbered sample slots. A guard plate screws down over the head to hold the tubes safely while the centrifuge is running.
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PUSHOMATIC Q U I C K
C O U P L I N G S
For Vacuum Filtration and Any Air, Hydraulic or Fluid Handling Application Pushomatic Seals
Eliminate Leakage.
DESIGNED FOR INSTRUMENTATION
Pushomatics are,safe.
Small a n d Lightweight. N o Spillage . . . No Leakage. Instant, O n e - H a n d Operation. Full Swivel Action Eliminates Hose Kinks. Write Dep't Ρ—F for Data
ACE GLASS INCORPORATED V I N E L A N D N E W JERSEY LOUISVILLE, KY., 6 3 9 - 4 1 SOUTH HANCOCK ST.
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Vacuum Distillation Column
For laboratory convenience, the vacuum distillation column intr:oduced last year by Glenlab has been: redesigned into a self-contained unit mounted in a metal shield. Facilities are provided for
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For further information, circle number 58 A on Readers' Service Card, page 55 A
58 A
The machine converts to a regular clinical centrifuge by removal of the Micro-Hematocrit head and replacing it with a regular 4-place slotted trunnion-type head or an angle-type head with up to 24 places. With regular heads in use, speeds up to 5000 r.p.m. can be obtained. 3
For further information, see coupon on page 55 A ANALYTICAL
CHEMISTRY
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rapid access to all parts requiring removal or adjustment during opera tion. The equipment was originally developed to coordinate with a stand ardization program relating to the use of ASTM-type distillation for the characterization of lubricating oils and reduced crudes.
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The apparatus includes two con denser jackets—one surrounding the delivery tube leading from the column to the product receiver, and a second vertical knock-back condenser for lighter materials. In most distillations, hot water is circulated through the lower condenser and tap water through the vertical condenser. The distilling flask is of 500-ml. capacity Vycor glass and equipped with a thermometer well and 35/25 socket joint. The silvered vacuum jacket is protected against thermal shock and expansion by inter nal-type expansion bellows, while the internal silvering on the vertical con denser is provided with a 1 / i -inch-wide full-length window. A 10/30 standard taper joint is included at the top of this condenser for the thermocouple. 4
A new guide for lab planners—a 48-page catalog and hand book of fume hood operation and design—has just been published by Laboratory Furniture Co. Because the design and construction of fume hoods are so im portant to safety, efficiency and convenience, we believe that "STEELAB Fume Hoods" . . . the only catalog of its size and scope devoted exclusively to fume hoods and associated equip ment . . . will be of special interest to everyone concerned with planning or specifying laboratory furniture. Write (on your letterhead, please) for your FREE copy of "STEELAB Fume Hoods". Visit our booth (No. 414) at the Chemical Exposition for a display of the latest STEELAB equipment.
LABORATORY
CO.
there is no better LABORATORY WARE The producers of VITREOSIL* (Vitreous Silica) will meet your most exacting requirements in transparent and nontransparent laboratory ware of the highest standards. Chemical purity, high resistance to heat shock as com pared to other ceramics, unusual electrical resistivity, best ultra-violet transmission (in transparent quality), plus low initial cost compared to platinum, are some features of VITREOSIL fused quartz. With our unusually large stock of standard items, includ ing transparent, glazed and unglazed crucibles, evaporating dishes, beakers and tubing and rods in all diameters and sizes, we also have facilities for fabrication of special items. Write today, giving us full details of your laboratory ware problem or ask for illustrated Technical Bulletin 22. *®
Concentrated Liquid Detergent
A concentrated liquid detergent, called 7X, has been developed by Linbro Chemical Co., Inc., for washing all types of laboratory glassware and surgical instruments. The detergent is made up of an anionic surface active agent and special solvents. Alkaline salts such as complex phosphates have been added as builders. The detergent is compatible with acids and alkalies and its pH varies only slightly with the concentration. It is said to be instantly and completely soluble in any concentration. There fore, continued use of 7X will eliminate undissolved particles and prevent par ticle redeposition. A 5 or 10% solution For further information, see coupon on page 55 A V O L U M E 2 7, N O . 1 1 , N O V E M B EB
FURNITURE
M I N E O L A , N E W Y O R K For further information, circle number 59 A-1 on Readers' Service Card, page 55 A
THERMAL AMERICAN FUSED QUARTZ CO., INC. 18-20 Salem Street, Dover, N e w Jersey Please send Technical B u l l e t i n 2 2 a n d
prices:
Company N a m e a n d Title Street City
Zone
State
For further information, circle number 59 A-2 on Readers' Service Card, page 55 A
1935
59 A
NEW PRODUCTS
prepared in an ordinary enameled pan can be reused through further addition of small amounts of detergent. The liquid is chemically mild and effective in either warm or cold water. 7X has proved particularly useful in tissue culture laboratories, where the surface of glassware must be thoroughly clean. 5
ing to their manufacturer, the American Agile Corp. Polyethylene is chemically inert, virtually unbreakable, and easily cleaned and installed. Polyethylene sink traps are particularly useful in laboratories where the disposal of chemicals is a problem. The traps are available only in one size to fit standard connections. Special tools for installation are unnecessary. 6
Plastic Sink Traps
Sink traps made of polyethylene offer several advantages over those of metallic and ceramic materials, accord-
Geiger-Counter Tube
A new Geiger-counter tube, designed for x-ray spectrographic work involving
elements such as phosphorus, silicon, and aluminum, has been announced by North American Philips, Inc. Resolving time of the counter tube is approximately 150microseconds; threshold is approximately 800 volts. Slope of the plateau is 10% maximum and the end of the plateau is over 1100 volts. This 10% figure is based on a rate of 100 counts per second at a sensitivity of 1 volt. Operating potential of the tube is 900 volts and its temperature range is —55° to 75° C. Life of the instrument is said to be unlimited by use. 7 Graphic Recorder
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