Thermo Scientific Cryo 740 Series, Руководство по эксплуатации и техническому обслуживанию

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Introduction
Warning Contact of liquid nitrogen or cold gas with the skin or eyes may
cause serious freezing (frostbite) injury. ▲
Handle liquid nitrogen carefully.
The extremely low temperature can freeze human flesh very rapidly. When
spilled on a surface the liquid tends to cover it completely and intimately,
cooling a large area. The gas issuing from the liquid is also extremely cold.
Delicate tissue, such as that of the eyes, can be damaged by an exposure to
the cold gas which would be too brief to affect the skin of the hands or
face.
Never allow any unprotected part of your body to touch objects cooled
by liquid nitrogen.
Such objects may stick fast to the skin and tear the flesh when you attempt
to free yourself. Use tongs to withdraw objects immersed in the liquid,
and handle the object carefully.
Wear protective clothing.
Protect your eyes with a face shield or safety goggles (safety glasses without
side shields do not give adequate protection). Always wear gloves when
handling anything that is, or may have been, in immediate contact with
liquid nitrogen. Insulated gloves are recommended, but heavy leather
gloves may also be used. The gloves should fit loosely, so that they can be
thrown off quickly if liquid should splash into them. When handling
liquid in open containers, it is advisable to wear high-top shoes. Trousers
(which should be cuffless if possible) should be worn outside the shoes.
The safe handling and use of liquid nitrogen in cryogenic refrigerators and
dewar flasks is largely a matter of knowing the potential hazards and using
common-sense procedures based on that knowledge. There are two
important properties of liquid nitrogen that present potential hazards:
1. It is extremely cold. At atmospheric pressure, liquid nitrogen boils at -
320° F (-196° C).
2. Very small amounts of liquid vaporize into large amounts of gas. One
liter of liquid nitrogen becomes 24.6 cu. ft. (0.7 m3) of gas.
7000740r7 Cryo Series 9-1 Thermo Scientific
Section 9
Appendix
Handling Liquid
Nitrogen