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Lake Shore Model 330 Autotuning Temperature Controller User's Manual
1.5
HANDLING LIQUID HELIUM AND LIQUID NITROGEN
Liquid Helium (LHe) and liquid nitrogen (LN
and LN
are not explosive, there are certain safety considerations when handling them.
2
1.5.1
Handling Cryogenic Storage Dewars
Operate all cryogenic containers (dewars) in accordance with manufacturer
instructions. Safety instructions are normally posted on the side of each dewar.
Keep cryogenic dewars in a well-ventilated place, protected from the weather, and
away from heat sources. Figure 3-1 shows a typical cryogenic dewar.
1.5.2
Liquid Helium and Nitrogen Safety Precautions
Transfer LHe and LN
and operate storage dewar controls in accordance with
2
manufacturer/supplier instructions. During transfer, follow all safety precautions
written on the storage dewar and recommended by the manufacturer.
WARNING
• Liquid helium is a potential asphyxiant and can cause rapid suffocation
without warning. Store and use in an adequately ventilated area. DO NOT
vent the container in confined spaces. DO NOT enter confined spaces
where gas may be present unless area is well-ventilated. If inhaled,
remove to fresh air. If not breathing, give artificial respiration. If
breathing is difficult, give oxygen. Get medical attention.
• Liquid helium can cause severe frostbite to exposed body parts. DO
NOT touch frosted pipes or valves. For frostbite, consult a physician
immediately. If a physician is unavailable, warm the affected parts with water that is near body
temperature.
Two essential safety aspects of handling LHe are adequate ventilation and eye and skin protection. Although
helium and nitrogen gases are non-toxic, they are dangerous because they replace air in a normal breathing
atmosphere. Liquid helium is an even greater threat because a small amount of liquid evaporates to create a
large amount of gas. Store and operate cryogenic dewars in open, well-ventilated areas.
When transferring LHe and LN
issuing from it. Protect eyes with full face shield or chemical splash goggles; safety glasses (even with side
shields) are inadequate. Always wear special cryogenic gloves (Tempshield CryoGloves
handling anything that is, or may have been, in contact with the liquid or cold gas, or with cold pipes or
equipment. Wear long sleeve shirts and cuffless trousers long enough to prevent liquid from entering shoes.
1.5.3
Recommended First Aid
Post an appropriate Material Safety Data Sheet (MSDS) obtained from the manufacturer/distributor at every
site that stores and uses LHe and LN
If a person exhibits symptoms of asphyxia such as headache, drowsiness, dizziness, excitation, excessive
salivation, vomiting, or unconsciousness, remove to fresh air. If breathing is difficult, give oxygen. If breathing
stops, give artificial respiration. Call a physician immediately.
If exposure to cryogenic liquids or cold gases occurs, restore tissue to normal body temperature (98.6 °F) by
bathing it in warm water not exceeding 105 °F (40 °C). DO NOT rub the frozen part, either before or after
rewarming. Protect the injured tissue from further damage and infection and call a physician immediately.
Flush exposed eyes thoroughly with warm water for at least 15 minutes. In case of massive exposure, remove
clothing while showering with warm water. The patient should not drink alcohol or smoke. Keep warm and
rest. Call a physician immediately.
Introduction
) may be used in conjunction with the Model 330. Although LHe
2
, protect eyes and skin from accidental contact with liquid or the cold gas
2
. The MSDS specifies symptoms of overexposure and first aid.
2
NON-
MAGNETIC
LIQUID
NON-
FLAMMABLE
HELIUM
KEEP
UPRIGHT
Figure 1-3. Cryogenic
Storage Dewar
or equivalent) when
®
1-7
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