A flat light emitting plate for simulating thermal radiation, the light emitting plate comprising:
- a. a main body made of a transparent material;
- b. a light emission area located on an upper surface of the light emitting plate for emitting light;
- c. at least one light source located on a lateral surface of the light emitting plate for irradiating light towards the main body;
- d. at least one detector located on a lateral surface of the light emitting plate for receiving light from the main body;
- and
- e. a regulating circuit for adjusting the intensity of light emitted by the light sources.