American Magnetics 135 & 136 Liquid Helium Level Instruments (CE-Marked) - Manual (Page 10)

vi Rev. 3
Foreword
Applicable Hardware
Applicable Hardware
The Model 135/136 has been designed to operate with an AMI Liquid
Helium Level Sensor. Operation with other equipment is not
recommended and may void the warranty.
General Precautions
Cryogen Safety
Personnel handling cryogenic liquids should be thoroughly instructed and
trained as to the nature of the liquids. Training is essential to minimize
accidental spilling. Due to the coldness of these materials, a cryogen
spilled on many objects or surfaces may damage the surface or cause the
object to shatter, often in an explosive manner.
Inert gases released into a confined or inadequately ventilated space can
displace sufficient oxygen to make the local atmosphere incapable of
sustaining life. Cryogenic liquefied gases are potentially extreme
suffocation hazards since a small amount of liquid will vaporize and yield
a very large volume of oxygen-displacing gas. Always ensure the location
where the cryogen is used is well ventilated. Breathing air with
insufficient oxygen content may cause unconsciousness without warning.
If a space is suspect, purge the space completely with air and test before
entry. If this is not possible, wear a forced-air respirator and enter only
with a co-worker standing by wearing a forced-air respirator.
Cryogenic liquids, due to their extremely low temperatures, will burn the
skin in a similar manner as would hot liquids. Never permit cryogenic
liquids to come into contact with the skin or allow liquid nitrogen to soak
clothing. Serious burns may result from careless handling. Never touch
uninsulated pipes or vessels containing cryogenic liquids. Flesh will stick
to extremely cold materials. Even nonmetallic materials are dangerous to
touch at low temperatures. The vapors expelled during the venting process
are sufficiently cold to burn flesh or freeze optic tissues. Insulated gloves
should be used to prevent frost-bite when operating valves on cryogenic
tanks. Be suspicious of valves on cryogenic systems; the extremes of
temperature they undergo causes seals to fail frequently.
In the event a person is burned by a cryogen or material cooled to
cryogenic temperatures, the following first aid treatment should be given
pending the arrival and treatment of a physician or other medical care
worker:
1. If any cryogenic liquid contacts the skin or eyes, immediately flush
the affected area gently with tepid water (102°F
−
105°F, 38.9°C
−
40.5°C) and then apply cold compresses.