Radiometry

High school (ages 12+)
Science & Technology

Name:

Date:

Step 1 · Read the article

Open the article and read it at the level above. Then answer the questions below in your own words.

https://smallwhale.org/articles/radiometry

Write what each word means, using the article.

Do not copy the article. Write two things you learned, the way you would explain them to a friend.

Answers below are taken from the article’s stored facts, so they match what the student read.

1. What is the fundamental quantities?Radiant intensity, radiance, irradiance, and radiant exitance, describing radiation power distribution
2. What is the key instrumentation?Radiometers employing thermal detectors (bolometers, thermopiles) or photon detectors (photodiodes)
3. What is radiometry and how is it different from photometry?Radiometry measures all kinds of light, even the invisible ones, and counts the energy itself. Photometry only cares about light that humans can see. So radiometry gives objective, physical numbers about light.
4. Why do scientists use radiometers instead of just looking at the light?Radiometers give precise, objective numbers about how much energy light carries. This helps scientists study stars, the Earth, and even industrial machines. It lets them compare measurements exactly.

Electromagnetic Radiation: Energy propagating as waves or photons, spanning radio waves, visible light, X-rays, and more.
Radiant Intensity: The power radiated from a point source per unit solid angle, measured in watts per steradian.
Irradiance: The power incident on a surface per unit area, measured in watts per square meter.