FLIR C3 User Manual

Theory of thermography
18
18.3.1 Planck’s law
Figure 18.3 Max Planck (1858–1947)
Max Planck (1858–1947) was able to describe the spectral distribution of the radiation
from a blackbody by means of the following formula:
where:
W
λb
Blackbody spectral radiant emittance at wavelength λ.
c
Velocity of light = 3 × 10
8
m/s
h Planck’s constant = 6.6 × 10
-34
Joule sec.
k Boltzmann’s constant = 1.4 × 10
-23
Joule/K.
T Absolute temperature (K) of a blackbody.
λ Wavelength (μm).
Note The factor 10
-6
is used since spectral emittance in the curves is expressed in Watt/
m
2
, μm.
Planck’s formula, when plotted graphically for various temperatures, produces a family of
curves. Following any particular Planck curve, the spectral emittance is zero at λ = 0, then
increases rapidly to a maximum at a wavelength λ
max
and after passing it approaches zero
again at very long wavelengths. The higher the temperature, the shorter the wavelength at
which maximum occurs.
#T559918; r. AN/42281/42281; en-US
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FLIR C3 Specifications

General

Temperature Range	-10°C to 150°C (14°F to 302°F)
Field of View	41° x 31°
Thermal Sensitivity	<0.10°C
Accuracy	±2 °C or ±2% of reading
Resolution	80 x 60 pixels
Image Storage	Internal memory
Connectivity	Wi-Fi
Display	3-inch touchscreen
Image Modes	Thermal, MSX, Picture-in-Picture
Digital Camera	640 x 480 pixels
File Format	JPEG
Battery Life	4 hours
Dimensions	125 x 80 x 24 mm (4.9 x 3.1 x 0.94 in)
Operating Temperature	-10°C to +50°C