Lake Shore Model 1015 User’s Manual
Glossary
A-3
liquid nitrogen (LN
2
)
. Also used for low temperature and superconductivity research
and for its refrigeration properties such as in freezing tissue cultures: minimum
purity 99.998%, O
2
8 ppm max. Boiling point at 1 atm = 77.4 K. Latent heat of
vaporization = 160 kilojoules per liter. Liquid density = 0.81 kilograms per liter.
EPA Hazard Categories: Immediate (Acute) Health and Sudden Release of
Pressure Hazards
DOT Label: Nonflammable Gas
DOT Class: Nonflammable Gas
DOT Name: Nitrogen, Refrigerated Liquid
DOT ID No: UN 1977
LSCI
. Lake Shore Cryotronics, Inc.
material safety data sheet (MSDS)
. OSHA Form 20 contains descriptive information
on hazardous chemicals under the OSHA Hazard Communication Standard (HCS).
These data sheets also provide precautionary information on the safe handling of
the gas as well as emergency and first aid procedures.
MKSA System of Units
. A system in which the basic units are the meter, kilogram,
and second, and the ampere is a derived unit defined by assigning the magnitude
4
"
x 10
-7
to the rationalized magnetic constant (sometimes called the permeability
of space).
NBS
. National Bureau of Standards. Now referred to as NIST.
NbTi
. Niobium-titanium. A superconductive alloy with a transition temperature
typically near 9 K in zero magnetic field.
National Institute of Standards and Technology (NIST)
. Government agency
located in Gaithersburg, Maryland and Boulder, Colorado, that defines
measurement standards in the United States.
parts per million (ppm
). 4 x 10
-6
is four parts per million.
pounds per square inch (psi)
. A unit of pressure. 1 psi = 6.89473 kPa. Variations
include psi absolute (psia) measured relative to vacuum (zero pressure) where one
atmosphere pressure equals 14.696 psia and psi gauge (psig) where gauge
measured relative to atmospheric or some other reference pressure.
prefixes
. SI prefixes used throughout this manual are as follows:
Factor
Prefix
Symbol
10
24
yotta
Y
10
21
zetta
Z
10
18
exa
E
10
15
peta
P
10
12
tera
T
10
9
giga
G
10
6
mega
M
10
3
kilo
k
10
2
hecto
h
10
1
deka
da
Factor
Prefix
Symbol
10
-1
deci
d
10
-2
centi
c
10
-3
milli
m
10
-6
micro
µ
10
-9
nano
n
10
-12
pico
p
10
-15
femto
f
10
-18
atto
a
10
-21
zepto
z
10
-24
yocto
y
RS-232C
. Bi-directional computer serial interface standard defined by the Electronic
Industries Association (EIA). The interface is single-ended and non-addressable.
setpoint
. The value selected to be maintained by an automatic controller.
1
serial interface
. A computer interface where information is transferred one bit at a
time rather than one byte (character) at a time as in a parallel interface. RS-232C is
the most common serial interface.