Instrument which measures heat radiation

At the other end he put a similar box with one end open to allow the sun to shine in. The sun shining on one end creates the temperature difference. The voltage measured will indicate how much energy is being absorbed by the exposed end. More than two little junctions were necessary. He put about fifty of them together to raise the voltage.

With a junction "thermopile", it was called, the temperature difference would be proportional to the amount of energy being absorbed.

This is called a passive cavity bolometer or radiometer since it is looking at the sun. Several uses were found for using this bolometer. By making it absorb all heat at all wavelengths, it could be used to measure radiation from any source. It could measure how much heat was radiating from the pot-belly stove in the corner.

It could measure the amount of heat being radiated from a wall. It could measure the amount of heat being radiated from a person. He pointed it at the moon and found that the moon wasn't radiating enough energy to produce light, indicating that the moon's light was reflected. And he made the first discernment that some things give off light without heat. He found out a great deal about the composition of the sun. His instrument was used to dispel the concept that the Earth's atmosphere acted exactly like a greenhouse by showing that the atmosphere selectively absorbs radiation, different from the glass of a greenhouse.

A bolometer, very much like the one just mentioned, is pictured in Figure 8. Here you see the box and a little window covered with plastic.

The plastic keeps the air currents out but lets infrared through. Inside that little window is a red shutter which will close the window to keep the light out, allowing the bolometer to equilibrate to room temperature.

Allowing the light in at the front permits infrared heat radiation to pass through. Then you can see a wire that is going into the center. In the center is the thermometer to measure the temperature inside this bolometer. Radar - is used to detect the direction and speed of an object by means of radiowaves, Salinometer - is used to determine salinity of solutions, Refractometer - is used to measure refractive indices. Galvanometer - measures electric current, Fluxmeter - measures magnetic flux, Endoscope - used to examine internal parts of the body.

Macmillan of Scotland invented Bicycle in Barometer was invented by E. Torricelli of Italy in Calculating Machine was invented by Pascal of France in Centigrade Scale was invented by A. Celsius of France in Question Detail. Answer: Option D Explanation: Radar - is used to detect the direction and speed of an object by means of radiowaves, Salinometer - is used to determine salinity of solutions, Refractometer - is used to measure refractive indices.

Which unit we use to express Nuclear sizes?