emissivity table

emissivity is a value determined by the object's material, surface shape, roughness, presence or absence of oxidation, measurement temperature, measurement wavelength, etc., and is expressed as the ratio "ε" of thermal radiation when blackbody furnace of the same temperature is observed in the same wavelength band.
Generally, emissivity "ε" is known as the value when a wavelength of 0.65 μm, i.e., an optical pyrometer, is used.
Even for the same material, emissivity can change due to the factors listed above, so please use this information as a reference.

>>For emissivity from 8 to 14 µm (thermopile/bolometer element area), please refer here.

emissivity (λ=0.65μm)

metal	emissivity		Oxide	emissivity
metal	solid	liquid	Oxide	emissivity
zinc	0.42	―	Alumel (surface oxidized)	0.87
Armel	0.37	―	Chromel (surface oxidized)	0.87
aluminum	0.17	0.12	Constantan (surface oxidized)	0.84
Antimony	0.32	―	porcelain	0.25～0.5
iridium	0.30	―	Cast iron (surface oxidized)	0.70
yttrium	0.35	0.35	55Fe. 37.5Cr. 7.5Al (surface oxidized)	0.78
uranium	0.54	0.34	70Fe. 23Cr. 5Al. 2Co (surface oxidized)	0.75
gold	0.14	0.22	80Ni. 20Cr (surface oxidized)	0.90
Silver	0.07	0.07	60Ni. 24Fe. 16Cr (surface oxidized)	0.83
Chrome	0.34	0.39	Stainless steel (surface oxidized)	0.85
Chromel P	0.35	―	Aluminum oxide	0.22～0.4
cobalt	0.36	0.37	Yttrium oxide	0.60
Constantin	0.35	―	Uranium oxide	0.30
zirconium	0.32	0.30	Cobalt oxide	0.75
mercury	―	0.23	Columbium oxide	0.55～0.71
Tin	0.18	―	Zirconium oxide	0.18～0.43
carbon	0.8～0.9	―	Tin oxide	0.32～0.60
tungsten	0.43	―	Cerium oxide	0.58～0.82
tantalum	0.49	―	Titanium dioxide	0.50
cast iron	0.37	0.40	iron oxide	0.63～0.98
titanium	0.63	0.65	Copper oxide	0.60～0.80
iron	0.35	0.37	Thorium oxide	0.20～0.57
copper	0.10	0.15	Vanadium Oxide	0.70
thorium	0.54	0.34	Beryllium Oxide	0.07～0.37
nickel	0.36	0.37	Magnesium oxide	0.10～0.43
8 0 N i . 2 0 C r	0.35	―
6 0 Ni . 2 4 Fe . 1 6 C r	0.36	―
platinum	0.30	0.38
9 0 Pt. 1 0 Rh	0.27	―
palladium	0.33	0.38
vanadium	0.35	0.35
Bismuth	0.29	―
beryllium	0.61	0.61
manganese	0.59	0.59
molybdenum	0.37	0.40
rhodium	0.24	0.30

emissivity (λ=0.9μm)

metal	emissivity
aluminum	0.10～0.23
gold	0.015～0.02
Chrome	0.36
cobalt	0.28～0.30
iron	0.33～0.36
copper	0.03～0.06
tungsten	0.38～0.42
titanium	0.50～0.62
nickel	0.26～0.35
platinum	0.25～0.30
molybdenum	0.28～0.36

alloy	emissivity
Inconel X	0.40～0.60
Inconel 600	0.28
Inconel 617	0.29
Inconel	0.85～0.93
Incoloy 800	0.29
Kanthal	0.80～0.90
stainless steel	0.3
Hastelloy X	0.3

Semiconductor	emissivity
silicon	0.69～0.71
germanium	0.6
Gallium arsenide	0.68

Ceramics	emissivity
Silicon carbide	0.80～0.83
Titanium carbide	0.47～0.50
Silicon nitride	0.89～0.90

Others	emissivity
Carbon Pigment	0.90～0.95
graphite	0.87～0.92

emissivity (λ=1.55μm)

metal	emissivity
aluminum	0.09～0.40
Chrome	0.34～0.80
cobalt	0.28～0.65
copper	0.05～0.80
gold	0.02
Rope board	0.30～0.85
lead	0.28～0.65
magnesium	0.24～0.75
molybdenum	0.25～0.80
nickel	0.25～0.85
Parajum	0.23
platinum	0.22
rhodium	0.18
Silver	0.04～0.10
tantalum	0.20～0.80
tin	0.28～0.60
titanium	0.50～0.80
tungsten	0.3
zinc	0.32～0.55

alloy	emissivity
brass	0.18～0.70
Chromel, Alumel	0.30～0.80
Constantin, Manganin	0.22～0.60
Inconel	0.30～0.85
Monell	0.22～0.70
Nichrome	0.28～0.85

Ceramics	emissivity
Alumina porcelain	0.3
Red Brick	0.8
White Brick	0.35
Silicon brick	0.6
Sillimanite bricks	0.6
Ceramics	0.5

Others	emissivity
Asbestos (plate, paper, cloth)	0.9
asphalt	0.85
carbon	0.85
Graphite	0.8
soot	0.95
Cement, concrete	0.7
cloth	0.8

Support