User's Manual
Table Of Contents
- 1 Disclaimers
- 2 Safety information
- 3 Notice to user
- 4 Customer help
- 5 Quick start guide
- 6 Register the camera
- 7 A note about ergonomics
- 8 Camera parts
- 9 Screen elements
- 10 Navigating the menu system
- 11 Handling the camera
- 11.1 Charging the battery
- 11.2 Installing and removing the camera battery
- 11.3 Turning on and turning off the camera
- 11.4 Adjusting the angle of lens
- 11.5 Adjusting the infrared camera focus manually
- 11.6 Autofocusing the infrared camera
- 11.7 Continuous autofocus
- 11.8 Operating the laser distance meter
- 11.9 Measuring areas
- 11.10 Connecting external devices and storage media
- 11.11 Moving files to a computer
- 11.12 Assigning functions to the programmable buttons
- 11.13 Using the camera lamp as a flash
- 11.14 Changing camera lenses
- 11.15 Neck strap
- 11.16 Hand strap
- 12 Saving and working with images
- 13 Working with the image archive
- 14 Achieving a good image
- 15 Working with image modes
- 16 Working with measurement tools
- 17 Working with color alarms and isotherms
- 18 Annotating images
- 19 Programming the camera (time-lapse)
- 20 Recording video clips
- 21 Screening alarm
- 22 Pairing Bluetooth devices
- 23 Configuring Wi-Fi
- 24 Fetching data from external FLIR meters
- 25 Changing settings
- 26 Cleaning the camera
- 27 Technical data
- 27.1 Online field-of-view calculator
- 27.2 Note about technical data
- 27.3 Note about authoritative versions
- 27.4 FLIR T530 24°
- 27.5 FLIR T530 42°
- 27.6 FLIR T530 24° + 14°
- 27.7 FLIR T530 24° + 42°
- 27.8 FLIR T530 24° + 14° & 42°
- 27.9 FLIR T530 42° + 14°
- 27.10 FLIR T540 24°
- 27.11 FLIR T540 42°
- 27.12 FLIR T540 24° + 14°
- 27.13 FLIR T540 24° + 42°
- 27.14 FLIR T540 24° + 14° & 42°
- 27.15 FLIR T540 42° + 14°
- 28 Mechanical drawings
- 29 Application examples
- 30 About FLIR Systems
- 31 Terms, laws, and definitions
- 32 Thermographic measurement techniques
- 33 The secret to a good thermal image
- 34 About calibration
- 34.1 Introduction
- 34.2 Definition—what is calibration?
- 34.3 Camera calibration at FLIR Systems
- 34.4 The differences between a calibration performed by a user and that performed directly at FLIR Systems
- 34.5 Calibration, verification and adjustment
- 34.6 Non-uniformity correction
- 34.7 Thermal image adjustment (thermal tuning)
- 35 History of infrared technology
- 36 Theory of thermography
- 37 The measurement formula
- 38 Emissivity tables
Thermographic measurement
techniques
32
32.1 Introduction
An infrared camera measures and images the emitted infrared radiation from an object.
The fact that radiation is a function of object surface temperature makes it possible for
the camera to calculate and display this temperature.
However, the radiation measured by the camera does not only depend on the tempera-
ture of the object but is also a function of the emissivity. Radiation also originates from
the surroundings and is reflected in the object. The radiation from the object and the re-
flected radiation will also be influenced by the absorption of the atmosphere.
To measure temperature accurately, it is therefore necessary to compensate for the ef-
fects of a number of different radiation sources. This is done on-line automatically by the
camera. The following object parameters must, however, be supplied for the camera:
• The emissivity of the object
• The reflected apparent temperature
• The distance between the object and the camera
• The relative humidity
• Temperature of the atmosphere
32.2 Emissivity
The most important object parameter to set correctly is the emissivity which, in short, is a
measure of how much radiation is emitted from the object, compared to that from a per-
fect blackbody of the same temperature.
Normally, object materials and surface treatments exhibit emissivity ranging from approx-
imately 0.1 to 0.95. A highly polished (mirror) surface falls below 0.1, while an oxidized
or painted surface has a higher emissivity. Oil-based paint, regardless of color in the visi-
ble spectrum, has an emissivity over 0.9 in the infrared. Human skin exhibits an emissiv-
ity 0.97 to 0.98.
Non-oxidized metals represent an extreme case of perfect opacity and high reflexivity,
which does not vary greatly with wavelength. Consequently, the emissivity of metals is
low – only increasing with temperature. For non-metals, emissivity tends to be high, and
decreases with temperature.
32.2.1 Finding the emissivity of a sample
32.2.1.1 Step 1: Determining reflected apparent temperature
Use one of the following two methods to determine reflected apparent temperature:
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