FLIR E60 User Manual

Theory of thermography
32
Figure 32.5 Wilhelm Wien (1864–1928)
The sun (approx. 6 000 K) emits yellow light, peaking at about 0.5 μm in the middle of
the visible light spectrum.
At room temperature (300 K) the peak of radiant emittance lies at 9.7 μm, in the far infra-
red, while at the temperature of liquid nitrogen (77 K) the maximum of the almost insignif-
icant amount of radiant emittance occurs at 38 μm, in the extreme infrared wavelengths.
Figure 32.6 Planckian curves plotted on semi-log scales from 100 K to 1000 K. The dotted line represents
the locus of maximum radiant emittance at each temperature as described by Wien's displacement law. 1:
Spectral radiant emittance (W/cm
2
(μm)); 2: Wavelength (μm).
32.3.3 Stefan-Boltzmann's law
By integrating Planck’s formula from λ = 0 to λ = ∞, we obtain the total radiant emittance
(W
b
) of a blackbody:
This is the Stefan-Boltzmann formula (after Josef Stefan, 1835–1893, and Ludwig Boltz-
mann, 1844–1906), which states that the total emissive power of a blackbody is propor-
tional to the fourth power of its absolute temperature. Graphically, W
b
represents the
area below the Planck curve for a particular temperature. It can be shown that the radiant
emittance in the interval λ = 0 to λ
max
is only 25% of the total, which represents about the
amount of the sun’s radiation which lies inside the visible light spectrum.
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FLIR E60 Specifications

General

Resolution	320 x 240 pixels
Thermal Sensitivity	<0.05°C at 30°C
Field of View	25° x 19°
Battery Life	4 hours
Spatial Resolution	1.36 mrad
Image Frequency	60 Hz
MeterLink	Yes
Laser Pointer	Yes
Text Annotation	Yes
Storage Media	SD card
Spectral Range	7.5 – 13 µm
Temperature Range	-20°C to +650°C
Display	3.5" LCD touchscreen
Focus	Manual
Accuracy	±2°C or ±2% of reading
Image Modes	Thermal, visual, MSX
Voice Annotation	Yes
Battery Type	Li-Ion battery
Minimum Focus Distance	0.4 m
Operating Temperature Range	-15°C to +50°C
Storage Temperature Range	-40°C to +70°C
Connectivity	Wi-Fi, USB
Image Storage	JPEG