Accession Number : AD0285381

Title :   METHODS FOR PRECISION TEMPERATURE CONTROL

Corporate Author : LITTLE (ARTHUR D) INC CAMBRIDGE MASS

Personal Author(s) : HEUCHLING,THEODORE P. ; BLACK,IGOR A. ; EVEREST,ANNE

Report Date : JUN 1962

Pagination or Media Count : 1

Abstract : IT IS POSSIBLE TO FABRICATE A MINIATURE, PARTIALLY SILVERED Pyrex dewar whose vacuum will not deteriorate appreciably for at least 6 months. Pyrex remains the best choice of material from which to make glass dewars. It is possible to make an oven with an accessible crystal whose insulation system has a heat loss of less than 300 milliwatts between -55 and +85 C. A partially silvered Pyrex outer dewar combined with our standard Pyrex inner dewar can improve the performance of the inner dewar by at least 100 milliwatts at the expense of about 2-1/4 in. increased volume. Using this insulation system in conjunction with a fully operational core, it is possible to make an oven accessible crystal which requires a total average input of less than 400 milliwatts to maintain the crystal at +85 C while ambient is at -55 C. It is possible to maintain the crystal temperature to within ! 0.10 C over the ambient temperature range of -55 to +80 C. (Author)

Descriptors :   *QUARTZ, *TEMPERATURE CONTROL, *THERMAL INSULATION, COATINGS, CRYSTAL OVENS, HEAT RESISTANT GLASS, MINIATURE ELECTRONIC EQUIPMENT, SEALS (STOPPERS), SILVER, STAINLESS STEEL, SWITCHING CIRCUITS, THERMOSTATS, VACUUM APPARATUS

Distribution Statement : APPROVED FOR PUBLIC RELEASE