Lake Shore Model 218 Temperature Monitor User’s Manual
Introduction
1-7
1.3 SAFETY
1.3.1 Handling Liquid Helium and Liquid Nitrogen
Liquid Helium (LHe) and liquid nitrogen (LN
2
) may be used in conjunction with
the Model 218. Although LHe and LN
2
are not explosive, there are certain
safety considerations when handling them.
1.3.1.1
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 1-1 shows a typical cryogenic
dewar.
1.3.1.2
Liquid Helium and Nitrogen Safety Precautions
Transfer LHe and LN
2
and operate storage dewar controls in accordance
with 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.
WARNING: 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
2
, protect eyes and skin from accidental contact with liquid or the
cold gas 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
Cryo-Gloves
®
or equivalent) when 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.
1.3.1.3
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
2
. The MSDS specifies symptoms of overexposure
and first aid.
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.
NON-
MAGNETIC
KEEP
UPRIGHT
LIQUID
LIQUID
HELIUM
HELIUM
NON-
FLAMMABLE
Figure 1-1. Cryogenic
Storage Dewar
Summary of Contents for 218S
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