VDAS TD1003 - Experiment

A benchtop unit to show the laws of radiant transfer from heat and light sources

PDF datasheet

The equipment has two parts; an aluminium Experiment Frame and a Control Box. The frame holds all the experiment parts and allows the user to slide the parts along easily for experiments of transfer over distances. The Control Box contains the electrical controls and displays of the measured readings.
The user fits different parts to the frame to measure the radiant transfer from light and heat sources. 

The heat source uses a variable low-voltage electric heater on a flat plate, creating a black body heat source of variable temperature. A thermocouple measures the heat source temperature. A moveable thermopile measures the heat radiation from the heat source at varying distances. TecQuipment include plates with different apertures, surface finishes and thermocouples. They allow extra experiments that show how surface finish affects emissivity and absorptivity, and the area factor for heat transfer. The light source uses a low voltage lamp inside an integrating sphere to create a diffuse light. Students can rotate the light source through a range of angles (shown on a protractor scale) for experiments in light direction. A moveable Lux Meter measures the light radiation from the light source at varying distances. 

TecQuipment includes different optical filters (coloured, neutral density and infrared block). They allow extra experiments that show how optical filters affect light transfer. 

A clear, multiline digital display on the Control Box shows temperatures and light or heat radiation. 

You can do tests with or without a computer connected. However, for quicker tests with easier recording of results, TecQuipment can supply the optional Versatile Data Acquisition System (VDAS). This gives accurate real-time data capture, monitoring and display, calculation and charting of all the important readings on a computer (computer not included).


  • Inverse Square Law (or Lambert's Distance Law/Area Law) - showing radiation is inversely proportional to distance squared
  • Stefan-Boltzmann Law - showing the relationship between radiation and source temperature
  • Kirchhoff's Law - showing that a body with good emissivity also has good absorbtivity
  • Area Factor -showing that radiation transfer depends on the exposed area of the radiant source


  • Inverse Square Law (or Lambert's Distance Law/Area Law) - showing radiation is inversely proportional to distance squared
  • Lambert's Direction Law (or Cosine Law) - showing that radiation is proportional to the cosine of the angle between the emitter and the receiver
  • Transmittance and Absorbance - showing that optical filters can reduce light intensity
VDAS-B (mkII) - Ancillary

A bench mounting versatile data acquisition system (VDAS) to allow computer-based data capture for a wide range of TecQuipment products.

VDAS TD1002 - Experiment

A base unit to support various experiments that demonstrate heat transfer.

VDAS TE85 - Experiment

Apparatus to allow students to investigate heat transfer by natural convection and radiation.