FLIR T530 User Manual

Theory of thermography
36
Figure 36.4 Blackbody spectral radiant emittance according to Planck’s law, plotted for various absolute
temperatures. 1: Spectral radiant emittance (W/cm
2
× 10
3
(μm)); 2: Wavelength (μm)
36.3.2 Wien’s displacement law
By differentiating Planck’s formula with respect to λ, and finding the maximum, we have:
This is Wien’s formula (after Wilhelm Wien, 1864–1928), which expresses mathematically
the common observation that colors vary from red to orange or yellow as the temperature
of a thermal radiator increases. The wavelength of the color is the same as the wavelength
calculated for λ
max
. A good approximation of the value of λ
max
for a given blackbody tem-
perature is obtained by applying the rule-of-thumb 3 000/T μm. Thus, a very hot star such
as Sirius (11 000 K), emitting bluish-white light, radiates with the peak of spectral radiant
emittance occurring within the invisible ultraviolet spectrum, at wavelength 0.27 μm.
Figure 36.5 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.
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FLIR T530 Specifications

General

Resolution	320 x 240 pixels
Thermal Sensitivity	< 30 mK
Digital Zoom	1-4x continuous
Image Modes	Thermal, MSX, Picture-in-Picture
Storage	SD card
Image Frequency	30 Hz
Accuracy	±2°C or ±2% of reading
Digital Camera	5 MP
Laser Distance Meter	Yes
Wi-Fi	Yes
Video Recording	Yes
Video Output	HDMI
Minimum Focus Distance	0.15 m (0.49 ft)
Operating Temperature Range	-15°C to 50°C (5°F to 122°F)
Storage Temperature Range	-40°C to 70°C (-40°F to 158°F)
Temperature Range	0°C to +650°C
Field of View	24° × 18°
Display	4-inch LCD touchscreen
Battery Life	Approx. 4 hours
Focus	Continuous, one-shot contrast, manual
Spectral Range	7.5-14 µm
Weight	1.3 kg (2.9 lbs)
Connectivity	Wi-Fi, USB
Lens Options	14°, 24°, 42°