Final control questions on the subject “heat engineering” The purpose and function of the subject. Working parameter. Status parameters. Base words and phrases

part of the spectrum. 
Stephan-Bolpsman law. Based on the results of the experiment, I. Stefan (1879) 
determined the following law: the radiation property of an absolute black body is 
directly proportional to the fourth degree of its absolute temperature. A. Bolsman 
theoretically proved this law in 1884. 
1
4
0
0
0
0
(
) ,
100
T
Е
J d
C









(10.7) 
where S
0
is the absolute blackbody radiation coefficient. [C
0
=5.67W/(m
2
K
4
)]; T is 
the temperature of the body surface, K. 
This law can also be written in the following forms: 
E
0
=G
0
T
4
, 
(10.8) 
For gray objects: 
4
4
0
0
(
)
(
)
100
100
T
T
E
E
C
C







10.9
where: G
0
– 5.67∙10-8W/(m
2
∙K) – Stefan's constant; S - radiation of a gray body; 
ɛ=E/E
0
is the blackness level of the gray matter. 
Kirchhoff's law. In 1882, G. Kirchhoff studied the difference between the 
absorption and distribution of heat rays of absolute black and gray bodies and 
discovered the following law: 
3
0
1
2
0
1
2
3
0
......
( ),
E
E
E
E
E T
A
A
A
A



