This product uses the same principle of near-infrared sensing as Agtron. When the infrared wavelength is between 780 to 1500nm, it is called a near-infrared due to its proximity to visible wavelengths. Many researches point out that the deeper the coffee roasting degree, the higher the carbonization degree of soluble organic matter in coffee beans, and the higher the absorption of near-infrared light. Therefore, when the measurement instrument emits near-infrared to the coffee to be tested, then measure the   reflected energy.  The lower the reflection indicates the deeper the roasting degree; the higher the reflective amount indicates a shallower roasting degree. SCA converts this reflection into a numerical value and calls it an Agtron number.