Variant A: Emissivity of object = 1,0
boundary condition:
object distance = 0
external optics transmission = 1.0
T = B / ln(R1/(R2*(S+O))+F)
T = object temperature in Kelvins
S = 16 Bit RAW value
R1 Planck R1 constant
R2 Planck R2 constant
B Planck B constant. Value range 1300 - 1600.
F Planck F constant. Value range 0.5 - 2.
O Planck O (offset) constant. Its a negative value.
ln() natural logarithm
Variant B: Emissivity of object < 1,0
boundary condition:
object distance = 0
external optics transmission = 1.0
now me must calculate the amount of radiance from reflected objects
for that, we need two auxiliary calculation
RAW_refl=R1/(R2*(e^(B/T_refl)-F))-O
T_refl = reflected temperature in Kelvins
RAW_refl is linear to amount of radiance of the reflected objects
e Euler's number
RAW_obj=(S-(1-Emissivity)*RAW_refl)/Emissivity
RAW_obj is linear to amount of radiance of the measured object
Emissivity = Emissivity of object
S = 16 Bit FLIR RAW value
now we use the formula from variant A and replace the 16-Bit-Image-Value "S" with the calculated RAW_obj
T_obj= B / ln(R1/(R2*(RAW_obj+O))+F)
T_obj = object temperature in Kelvins
R1 Planck R1 constant
R2 Planck R2 constant
B Planck B constant. Value range 1300 - 1600.
F Planck F constant. Value range 0.5 - 2.
O Planck O (offset) constant. Its a negative value.