polarimeter

This term is a technical noun used almost exclusively within the fields of chemistry, pharmacology, and physics. It describes a specialized piece of laboratory equipment, and as such, it carries a neutral, scientific register. It is rarely encountered in general conversation outside of academic or industrial laboratory settings.

Because it refers to a specific physical device, it follows standard English countability rules for equipment. It is not a mass noun or a collective noun, meaning it is used with singular and plural articles and numbers as expected for a tangible tool.