A luminance meter is a measuring instrument for light and color measurement. Luminance meter is one of the common instruments and equipment necessary for every chemical analysis laboratory, and has been widely used in various quantitative and qualitative analysis.

principle. The luminance meter mainly uses a pair of light holes with a certain distance to receive the luminous flux of a fixed solid angle and a fixed light projection area. This value does not change with the distance of the object, as long as the surface area of ​​the object is large enough. In order to aim at the object to be measured, an imaging system is often used.
The measured light source of the Luminance meter is imaged on the mirror with a hole (front light hole) after passing through the objective lens, and a part of it is received by the human eye through the mirror and eyepiece, so as to aim and monitor the clear imaging surface and the mirror with a hole coincident; Part of the light passes through the small hole on the mirror and reaches the V(λ) receiver through the rear light hole. The brightness value is displayed with a pointer or a digital meter.
Through the above introduction and analysis of the Luminance meter and its principle, hope it helps you.