1. Global Perspective, Local Commitment

2. What is Infrared? It is the energy that is emitted from all objects.

3. Electromagnetic Spectrum
VISIBLE UV
Infrared
X-rays
Gamma
Rays
Radio
EHF SHF UHF VHF HF MF LF VLF
0.1A 1A
100A 1µ
100µ
1cm
1mm 1m
1km
100km
Wavelength 30 20 15 10 8 6 4 3 2
1.5 1
0.8
0.6
0.4
Wavelength µm
Infrared Measurement Region TV
mm WAVE
1000 C
WHAT PLANCK’S RADIATION LAW MEANS:
EXPLAINS WHY CAN “FEEL” HEAT FROM WARM OBJECT - MOST THERMAL ENERGY IS IN IR
SHOWS WHY INFRARED (IR) IS PROPER SPECTRAL BAND TO MEASURE TEMPERATURE
ALLOWS ANALYSIS OF MEASURED HEAT SIGNAL

4. The Object Important Parameters Temperature range Size and shape
Distance from sensor
Material type
Movement
453¡C
SP1 470¡C
EMS ¯.85 S T
The object is the initial part of the IR system and any discussion of infrared theory and analysis must start with an understanding of the characteristics of the object being measured. All objects above absolute zero will radiate electromagnetic energy in the infrared spectrum.
Understanding the object’s parameters is important in designing an appropriate IR system. For temperature range, do you just need to measure the process, or start-up temperatures as well. Are you measuring discrete, separate objects, or a continuous whole? The speed of any moving objects most fall within an instrument’s response time.
Object

5. Sources of Infrared Energy
Reflectivity, Transmissivity, Emissivity
Object
Ambient R
Sensor T
Infrared energy incident upon an object will either be reflected off the object, transmitted through the object or absorbed and emitted.
Shiny metals reflect energy off an object.
Glass and plastic will transmit energy through an object.
Energy that is absorbed by an object will heat it. This energy is then emitted at the object’s surface and can be measured by an infrared thermometer. IR temperature measurement tries to isolate the emitted energy in order to obtain an accurate reading. E
R + T + E = 1 (Total collected Energy)
R = Reflected Energy
T = Transmitted Energy
E = Emitted Energy from Object
SIGNAL COMPOSED OF E + R + T.
E IS DESIRED COMPONENT
REFLECTED MAKES READING TOO HIGH
TRANSMITTED MAKES READING TOO HIGH

6. Emissivity-the Ability of an Object to Emit Energy
Measuring errors are often caused by IR energy being reflected