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

The 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. 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: eg Kirchhoff’s law of radiation, the Stefan-Boltzmann law, Lambert’s distance and direction law.

Colours can be sSTup 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.

Technical details

Specification:

Thermal radiator and thermopile for the investigation of thermal radiation

Adjustable radiant power of thermal radiator and light source

3 colour filters with holder (red, green, infrared), slit diaphragm

Thermopile for measuring radiant power

Luxmeter for measuring illuminance

Light source and luxmeter for the investigation of illuminance

Absorption plate and reflection plate with thermocouples for the investigation of Kirchhoff’s laws

Thermocouple for measuring the temperature

Technical data:

Thermal radiator

Material: AlMg3, black anodized

Output: 400W at 230V, 340W at 120V

Max. achievable temperature: 300°C

Radiant area, LxW: 200x200mm

Light source

Halogen lamp

Output: 42W

Luminous flux: 630lm

Colour temperature: 2900K

Range of rotation on both sides: 0… 90°

Alternative illuminated surface

Diffusing lens, LxW: 193x193mm or

Orifice plate, Ø 25mm

Optical elements to insert

Slit diaphragm

3 colour filters: red, green, infrared

Absorption plate and reflection plate with thermocouple type K, matt black lacquered

Measuring ranges

Illuminance: 0…1000 lux

Temperature: 2x 0…200°C

Radiant power: 0…1000W/m2

230V, 50Hz, 1 phase

230V, 60Hz, 1 phase; 120V, 60Hz, 1 phase.