Lake Shore Model 475 Gaussmeter User’s Manual
A-2
Units for Magnetic Properties
Table A-2. Recommended SI Values for Physical Constants
Quantity
Symbol
Value (SI units)
Permeability of Vacuum
µ
0
4
π
× 10
–7
H m
–1
Speed of Light in Vacuum
c
2.9979 × 10
8
m s
–1
Permitivity of Vacuum
ε
0
= (µ
0
c
2
)
–1
8.8542 × 10
–12
F m
–1
Fine Structure Constant, µ0ce2/2h
α
α
–1
0.0073
137.0360
Elementary Charge
e
1.6022 × 10
–19
C
Plank's Constant
h
h = h/2
π
6.6262 × 10
–34
J Hz
–1
1.0546 × 10
–34
J s
Avogadro's Constant
N
A
6.0220 × 10
23
mol
-1
Atomic Mass Unit
1 u = 10
–3
kg mol
–1
/N
A
1.6605 × 10
–27
kg
Electron Rest Mass
m
e
0.9109 × 10
–30
kg
5.4858 × 10
–4
u
Proton Rest Mass
m
p
1.6726 × 10
–27
kg
1.0073 u
Neutron Rest Mass
m
n
1.6749 × 10
–27
kg
1.0087 u
Magnetic Flux Quantum
φ
= h/2e
h/e
2.0679 × 10
–15
Wb
4.1357 × 10
–15
J Hz
–1
C
–1
Josephson Frequency-Voltage Ratio
2e/h
483.5939 THz V
–1
Quantum of Circulation
h/2m
e
h/m
e
3.6369 × 10
-4
J Hz
–1
kg
–1
7.2739 × 10
-4
J Hz
–1
C
–1
Rydberg Constant
R
∞
1.0974 × 10
7
m
–1
Proton Moment in Nuclear Magnetons
µ
p
/µ
N
2.7928
Bohr Magneton
µ
B
= eh/2m
e
9.2741 × 10
–24
J T
–1
Proton Gyromagnetic Ratio
γ
p
2.6752 × 10
8
s
–1
T
–1
Diamagnetic Shielding Factor, Spherical H
2
O Sample
1 +
σ
(H
2
O)
1.0000
Molar Mass Constant
R
8.3144 J mol
–1
K
–1
Molar Volume, Ideal Gas (T
0
= 273.15K, p
0
= 1 atm)
V
m
= RT
0
/p
0
0,0224 m
3
mol
–1
Boltzman Constant
k = R/N
A
1.3807 × 10
–23
J K
–1
Stefan-Boltzman Constant
σ
= (
π
2
/60) k
4
/h
3
c
2
5.6703 × 10
–8
W m
–2
K
–4
First Radiation Constant
c
1
= 2
π
hc
2
3.7418 × 10
–16
W m
–2
Second Radiation Constant
c
2
= hc/k
0.0144 mK
Gravitation Constant
G
6.6720 × 10
–11
N m
2
kg
–2
Data (abbreviated to 4 decimal places) from CODATA Bulletin No. 11, ICSU CODATA Central Office,
19 Westendstrasse, 6 Frankfurt/Main, Germany. Copies of this bulletin are available from this office.