9027.50.40.50 - Photometers

This HTS subcategory, specifically 9027.50.40.50, encompasses **photometers** that fall within the broader classification of instruments and apparatus using optical radiations. Photometers are designed to measure the intensity of light. They operate by detecting and quantifying light in the visible spectrum, and in some cases, extending into ultraviolet or infrared ranges, to determine its brightness or intensity. This can include devices used for laboratory analysis, environmental monitoring, or quality control where precise light measurement is critical.

It is important to distinguish this category from its sibling, 9027.50.40.15, which covers instruments and apparatus for chemical analysis. While photometers might be *used* in chemical analysis, this specific subcategory is for the photometer itself when its primary function is light intensity measurement, rather than the broader analysis of chemical composition or properties. Similarly, it differs from 9027.50.40.20, which focuses on thermal analysis instruments, and 9027.50.40.60, which serves as a residual category for other optical radiation instruments not otherwise specified.

As 9027.50.40.50 is a leaf node within the HTS structure, there are no further subdivisions. Therefore, classification within this category hinges on the instrument's explicit function as a photometer and its reliance on optical radiation for measurement. Examples might include lux meters, colorimeters (when their primary function is to measure light absorption/transmission for quantitative analysis), or general-purpose photometers used for optical density measurements.