Vacuum Flask - Research and Industry

Research and Industry

In laboratories and industry, vacuum flasks are often used to store liquids which become gaseous at well below ambient temperature, such as oxygen and nitrogen; in this case, the leakage of heat into the extremely cold interior of the bottle results in a slow "boiling-off" of the liquid so that a narrow unstoppered opening, or a stoppered opening protected by a pressure relief valve, is necessary to prevent pressure from building up and eventually shattering the flask. The insulation of the vacuum flask results in a very slow "boil", and thus the contents remain liquid for long periods without refrigeration equipment.

Vacuum flasks have been used to house standard cells, and ovenized Zener diodes, along with their printed circuit board, in precision voltage regulating devices used as electrical standards. The flask helped with controlling the Zener temperature over a long time span, and was used to reduce variations of the output voltage of the Zener standard due to temperature fluctuation, to within a few parts per million.

One notable use was by Guildline Instruments, of Canada, in their "Transvolt", model 9154B, saturated standard cell, which is an electrical voltage standard. Here, a silvered vacuum flask, that was encased in foam insulation, and using a large glass vacuum plug, held the saturated cell. The voltage output of the device was 1.018 volts, and was held to within a few parts per million.

The principle of the vacuum flask makes it ideal for storing certain types of rocket fuels, and NASA used it extensively in the propellant tanks of the Saturn launch vehicles in the 1960s and 1970s.