Laws of Radiant Heat Transfer and Exchange


Thermal radiation is a non-material-bound energy transport by means of electromagnetic oscillations in a certain wavelength range. Anybody with a temperature above zero Kelvin emits radiation known as thermal radiation. Thermal radiation includes UV radiation, light radiation and infrared radiation. Light radiation covers the wavelength range visible to the human eye.

The TE 110 experimental unit contains two radiation sources: a heat radiator and a light emitter. Thermal radiation is detected by means of a thermopile. Light radiation is recorded by means of a luxmeter with photodiode. Various optical elements such as apertures, absorption plates or color filters can be set up between the emitter and the detector. All components are mounted on an optical bench. The distance between the optical elements can be read from a scale along the optical bench.

Luxmeter, thermopile and light emitter can be rotated to study how the angle of incidence affects the radiation intensity. The angles are read off the angular scale.

The optical elements are used to investigate the reflection, absorption and transmission of different materials at different wavelengths and temperatures. The radiant power of both emitters can be adjusted. The aim of the experiments is to check optical laws: e.g., Kirchhoff’s law of radiation, the Stefan-Boltzmann law, Lambert’s distance and direction law.

The measured values are displayed digitally on the measuring amplifier. The measured values are transmitted directly to a PC via USB where they can be analyzed using the software included.


  1. Convective heat transfer demonstration should be possible with the training set.
  2. For the study of thermal radiation, there should be a thermal radiator and a thermopile.
  3. For lighting research, there should be a light source and lux meter.
  4. For the study of Kirchhoff’s laws, there should be an absorption plate and a thermocouple reflection plate.
  5. Thermal radiator and light source should be adjustable resistance.
  6. There should be 3 color filters (red, green, infrared) with holder, slit diaphragm.
  7. Must have lux meter to measure luminance.
  8. It should have a thermocouple to measure the temperature.
  9. It should be thermopile to measure radiant power.
  10. DAQ system will be available
  11. ADF software for data acquisition via Ethernet under Windows 8.1, 10
  12. The devices should be delivered fully assembled tested and ready to operate.

Technical Details

  1. Thermal radiator
  2. Material: AlMg 3, black anodized
  3. Output: 400W 230V
  4. Maximum achievable temperature: 300 ° C
  5. Bright field plate, LxW: 200x200mm
  6. Light source: Halogen lamp
  7. Output: 50W
  8. Luminous flux: 1185lm
  9. Color temperature: 2950K
  10. Rotation range on both sides: 0… 90 °
  11. Optional illuminated surface
  12. Radiating lens, LxW: 193x193mm or
  13. Orifice plate, Ø 25mm
  14. Optical elements to be added
  15. Slit diaphragm
  16. 3 color filters: red, green, infrared
  17. Absorption plate and reflection plate with thermocouple type K, matt black lacquered

Measuring ranges:

  • Illumination: (0… 1000 lux)
  • Temperature: 2pieces (0… 200 ° C)
  • Radiant power: 0… 1000W / m 2


  • Lambert’s law of direction
  • Lambert’s law of distance
  • Stefan-Boltzmann law
  • Kirchhoff’s laws
  • Radiation absorption
  • Radiation reflection
  • Study of radiation emission thermal and light radiation
  • Influence of distance and angle of incidence
  • Wide range of experiments

Required for operation

  • PC with Windows recommended