Measure the Illuminance of White and Color LED Lights. The LT45 LED light meter is useful for measuring and optimizing environmental light levels in a wide range of environments, including office buildings, manufacturing plants and warehouses, university campuses, schools, hospitals, and many other locations. OSHA regulates workplace lighting because illumination must be adequate for assigned tasks, and light meters are used to verify regulatory compliance, as well as state and local public safety codes and ordinances. Use of LED lighting is on the rise because it is more efficient to operate, it emits stable, high quality illumination, and the technology is dropping in price. The LT45 comes with a 9-volt battery, protective sensor cover, hard case, and user manual.