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ANALYTICAL
INSTRUMENTATION
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SPEED OVEN ψ Dries More Than Twice as Fast Clean hot air from above plut radiant heat from be low removes moisture and solvents rapidly. Ready to use in 2 minutes.
Solders
SPEED DESICCATOR NO. 5150 Solid cast aluminum, conducts heat away fast. Visible indicating desiccator. Pro tected grease seal and vacuum breaker.
NO. 5175 FAN-COOLCD
SPEED ν DESICCATOR ψ Higher cooling capacity for continuous w o r k . Fan takes heat away from bowl to maintain cooling efficiency.
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NO. 415 FORCE-COOIED
, SPEED ψ DESICCATOR Fan inside drying cool ing chamber circulates air through bulky loads as fan below chamber carries heat away. ÏOV2 inch diameter by 9 inch deep inside. Write Dept, S-I Today for Full Description and Prices. CONTROL
EQUIPMENT
HARRY W. DIETERT COMPANY 9330 ROSEIAWN
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example of the use of this'instrument is shown in a recording of the oxygen consumption of Chlorella cells by respiration in the dark and the production of oxygen upon illumination of the suspension. We have quoted so extensively from this issue of Science primarily because each of these contributions holds much of promise for the analyst as well as illustrating instrumental advances. There seems to be increasing justification for our contention that the best initial investment in setting up a modern analytical research laboratory is a good electronic recorder. Electronic techniques and practices are highly developed, and the principal problem in any new application or method is largely one of finding an appropriate primary element or transducer.
DETROIT 4, MICH.
Information which one would ordinarily regard as more properly referred to the workshop is contained in an article by M. D. Pugh on "Solders and Soldering Technique in Instrument Making" [Instrument Maker, 19,134 (1951) ]. Actually, this information is most extensive and useful for the instrument designer and the research worker. When one considers the diversity of metals and alloys and the need for special forms of sealing, it can be seen that the elementary concept of acid-core and rosin-core solder is but a small part of the story. It is said that one manufacturer lists more than 100,000 items of solder in bars, sticks, solid wire, strip, foil, powder, and single and multipleflux core types of wire. Available also are preformed rings, pellets, washers, and other shapes in thousands of types and sizes. A new technique for sealing windows into instrument cases mounts the glass in a metal ring with uncured rubber. The solder, which is applied from the outside of the case and ring, gives a flush-soldered joint. The uncured rubber used to hold the glass is subsequently self cured in the rim. This results in a positive, flexible seal, which can withstand pressures up to 100 pounds per square inch. The intermediate rubber ring provides resistance to thermal shock of the glass and the latter can be removed, if necessary, by means of a circular iron. New materials, new requirements, and more rigid specifications require new techniques and, though their role ma5' be humble, they often determine success or failure. Among the more maddening experiences with electrical or electronic instruments is the occasional "coldsoldered" joint.
CHEMISTRY
AVAILABLE
REPRINTS OF a*td
Βψηραάία
1st 2nd 3rd 4th 5th
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REVIEW. REVIEW. REVIEW. REVIEW. REVIEW.
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2 / W OfL&uUia+U 3rd 4th 5th 6th
REVIEW. REVIEW. REVIEW. REVIEW.
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