Product Manual
Table Of Contents
- 1 Disclaimers
- 2 Safety information
- 3 Notice to user
- 4 Customer help
- 5 Quick Start Guide
- 6 Description
- 7 Operation
- 7.1 Charging the battery
- 7.2 Turning on and turning off the camera
- 7.3 Saving an image
- 7.4 Recalling an image
- 7.5 Deleting an image
- 7.6 Deleting all images
- 7.7 Measuring a temperature using a spotmeter
- 7.8 Measuring the hottest temperature within an area
- 7.9 Measuring the coldest temperature within an area
- 7.10 Hiding measurement tools
- 7.11 Changing the color palette
- 7.12 Changing image mode
- 7.13 Changing the temperature scale mode
- 7.14 Setting the emissivity as a surface property
- 7.15 Setting the emissivity as a custom material
- 7.16 Changing the emissivity as a custom value
- 7.17 Changing the reflected apparent temperature
- 7.18 Changing the settings
- 7.19 Updating the camera
- 8 Technical data
- 9 Declaration of conformity
- 10 Cleaning the camera
- 11 Application examples
- 12 About FLIR Systems
- 13 Glossary
- 14 Thermographic measurement techniques
- 15 History of infrared technology
- 16 Theory of thermography
- 17 The measurement formula
- 18 Emissivity tables
Theory of thermography
16
• A selective radiator, for which ε varies with wavelength
According to Kirchhoff’s law, for any material the spectral emissivity and spectral absorp-
tance of a body are equal at any specified temperature and wavelength. That is:
From this we obtain, for an opaque material (since α
λ
+ ρ
λ
= 1):
For highly polished materials ε
λ
approaches zero, so that for a perfectly reflecting materi-
al (i.e. a perfect mirror) we have:
For a graybody radiator, the Stefan-Boltzmann formula becomes:
This states that the total emissive power of a graybody is the same as a blackbody at the
same temperature reduced in proportion to the value of ε from the graybody.
Figure 16.8 Spectral radiant emittance of three types of radiators. 1: Spectral radiant emittance; 2: Wave-
length; 3: Blackbody; 4: Selective radiator; 5: Graybody.
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