Spectroradiometers are designed to measure the spectral power distributions of illuminants. They operate almost like spectrophotometers in the visible region

Visible spectrum

The visible spectrum is the portion of the electromagnetic spectrum that is visible to the human eye. Electromagnetic radiation in this range of wavelengths is called visible light or simply light. A typical human eye will respond to wavelengths from about 390 to 750 nm. In terms of...

. They are commonly used to evaluate and categorize lighting for sales by the manufacturer, or for the customers to confirm the lamp they decided to purchase is within their specifications.

Spectroradiometers are frequently used to calibrate LCD and CRT displays such as on laptops and HDTVs.