Abstract

The effective emissivity of nonisothermal diffuse cavity radiators is numerically computed as a function of the bandwidth of the radiation. The deviation of the integrated cavity emissivity due to nonisothermality is small for small distances of the detector from the cavity, independent of the bandwidth. Consideration is given to the observed wavelength characteristic of the effective emissivity.

© 1985 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. R. E. Bedford, C. K. Ma, “Emissivities of Diffuse Cavities: Isothermal and Nonisothermal Cones and Cylinders,” J. Opt. Soc. Am. 64, 339 (1974).
    [CrossRef]
  2. R. E. Bedford, C. K. Ma, “Emissivities of Diffuse Cavities, II: Isothermal and Nonisothermal Cylindro-Cones,” J. Opt. Soc. Am. 65, 565 (1975).
    [CrossRef]
  3. R. E. Bedford, C. K. Ma, “Emissivities of Diffuse Cavities. III. Isothermal and Nonisothermal Double Cones,” J. Opt. Soc. Am. 66, 724 (1976).
    [CrossRef]
  4. S. Chen, Z. Chu, H. Chen, “Precise Calculation of the Integrated Emissivity of Baffled Blackbody Cavities,” Metrologia 16, 69 (1980).
    [CrossRef]
  5. Y. Ohwada, “Evaluation of the Integrated Emissivity of a Black Body.” Jpn. J. Appl. Phys. 23, L167 (1984).
    [CrossRef]
  6. Y. Ohwada, “Evaluation of Effective Emissivities of Nonisothermal Cavities,” Appl. Opt. 22, 2322 (1983).
    [CrossRef] [PubMed]
  7. Y. Ohwada, “Formulation of Multiple Reflections Within a Diffuse Cavity Radiator: Comments,” Appl. Opt. 23, 4182 (1984).
    [CrossRef]
  8. The notation Δf (P,D) in Eqs. (5)–(7) in Ref. 6 is not adequate. In accordance with the notation for other angle factors used in Ref. 6, Δf(P,D) should be revised to Δf(D,P).

1984

Y. Ohwada, “Evaluation of the Integrated Emissivity of a Black Body.” Jpn. J. Appl. Phys. 23, L167 (1984).
[CrossRef]

Y. Ohwada, “Formulation of Multiple Reflections Within a Diffuse Cavity Radiator: Comments,” Appl. Opt. 23, 4182 (1984).
[CrossRef]

1983

1980

S. Chen, Z. Chu, H. Chen, “Precise Calculation of the Integrated Emissivity of Baffled Blackbody Cavities,” Metrologia 16, 69 (1980).
[CrossRef]

1976

1975

1974

Bedford, R. E.

Chen, H.

S. Chen, Z. Chu, H. Chen, “Precise Calculation of the Integrated Emissivity of Baffled Blackbody Cavities,” Metrologia 16, 69 (1980).
[CrossRef]

Chen, S.

S. Chen, Z. Chu, H. Chen, “Precise Calculation of the Integrated Emissivity of Baffled Blackbody Cavities,” Metrologia 16, 69 (1980).
[CrossRef]

Chu, Z.

S. Chen, Z. Chu, H. Chen, “Precise Calculation of the Integrated Emissivity of Baffled Blackbody Cavities,” Metrologia 16, 69 (1980).
[CrossRef]

Ma, C. K.

Ohwada, Y.

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (6)

Fig. 1
Fig. 1

Deviation of the effective emissivity vs the distance from the base or apex for λ0 = 0.65 × 10−4 cm and δ = 0.5. The dashed curves correspond to T1(l), the solid curves correspond to T2(l), where T0 = 1300 K. R is the radius of the cavity opening; Cy is the cylinder; C0 is the cone; D0C0 is the double cone.

Fig. 2
Fig. 2

Deviation of the integrated cavity emissivity vs the distance of the detector from the cavity opening for a cylinder with L = 4.0, R = 0.5, and ε = 0.7. The dashed curves correspond to T1(l) and the solid curves correspond to T2(l), where T0 = 1300 K, and T in the figure means total radiation.

Fig. 3
Fig. 3

Absolute value of ΔEI vs the half-bandwidth-to-center wavelength ratio for a cone with L = 2, R = 0.5, and ε = 0.5, where H = 500. The curves are labeled according to λ0 in units of micrometers.

Fig. 4
Fig. 4

Relative spectral radiance of a blackbody at a temperature T(Q) vs wavelength. The solid curve corresponds to T(Q) = 1300 K and the dashed curve corresponds to T(Q) = 1287 K.

Fig. 5
Fig. 5

Absolute value of ΔEI vs the center wavelength for a cone with L = 2, R = 0.5, and ε = 0.5, where H = 500.

Fig. 6
Fig. 6

Absolute value of ΔEI vs the half-bandwidth-to-center wavelength ratio for a cone with L = 2,R = 0.5, and ε = 0.5, where H = 500. The curves are labeled according to λ0 in units of micrometers.

Tables (1)

Tables Icon

Table I Temperature for the Weighted Average Radiant Exitance for H = 0 and T0 = 1300 K

Equations (17)

Equations on this page are rendered with MathJax. Learn more.

E ( Q ) = M ( Q ) / M b ( Q ) .
M n ( Q ) = M n 1 ( Q ) + ρ p = 1 N [ M n 1 ( P ) M n 2 ( P ) ] F d Q Δ P for Q = 1 , , U and n 2 .
M b ( Q ) = 0 L b [ λ , T ( Q ) ] G ( λ ) d λ ,
G ( λ ) = { 1 for λ 0 + δ λ 0 λ λ 0 δ λ 0 0 for λ > λ 0 + δ λ 0 or λ < λ 0 δ λ 0 for 0 δ < 1 .
L b [ λ , T ( Q ) ] = C 1 / [ λ 5 ( exp { C 2 / [ λ T ( Q ) ] } 1 ) ] ,
T 1 ( l ) = T 0 ( 1. 0.01 l / L ) ,
T 2 ( l ) = T 0 [ 1. 0.04 ( l L / 2 ) 2 / L 2 ]
Δ E = E i ( Q ) E 0 ( Q ) for i = 1 , 2 ,
E I ( T i ) = Q = 1 K M ( Q ) F D Δ Q / M b ( A ) F D B
F D B = Q = 1 K F D Δ Q .
M b ( A ) = Q = 1 K M b ( Q ) F D Δ Q / F D B .
T ( A n ) = T ( A n 1 ) + N n / 10 n for 0 N n and n 1 ,
| 1 M b ( A n ) / M b ( A ) | < 10 6 .
Δ E I = E I ( T i ) E I ( T 0 ) for i = 1 , 2 ,
Δ E P = Δ T ( E P / T ) ,
( Δ E P ) / λ = C 2 exp [ C 2 / ( λ T ) ] ( C 2 λ T { exp [ C 2 / ( λ T ) ] 1 } ) Δ T / ( λ 3 T 3 { exp [ C 2 / ( λ T ) ] 1 } 2 ) ,
C 2 λ T { exp [ C 2 / ( λ T ) ] 1 } = λ T n = 2 [ C 2 / ( λ T ) ] n / n ! < 0 .

Metrics