Luxmeter

A luxmeter is a mobile device for measuring the level of illumination in space. The name comes from the Greek words meaning "light" and "measure". It belongs to the category of photometers. Often luxmeters additionally measure other characteristics of light: ripple coefficient, brightness, etc. The simplest luxmeter consists of a photodetector (semiconductor photocell), a power source and a photocurrent recorder (light indicator). A microammeter with a scale, which is graduated in lux, acts as a recorder. The indicator can be mechanical (with an arrow) or digital (display).