The measurement of light has become common in today’s world for a multitude of different reasons, from checking the levels of lighting for set design or photography to making sure they are at the optimum level for the health and safety of employees.
Most people have heard of the measure of light intensity known as the lumen. The candela is the base unit for luminous intensity (around 1 candela being given off by one candle). One candela for every steradian – the area within a cone ship that starts from the light source – is called a lumen.
To measure light we need to know the number of lumens that fall onto a surface, and this is known as lux. A single lux is basically one lumen for every square meter, and to measure lux you need a lux meter.
A lux meter, also sometimes referred to simply as a light meter, is the simplest way of measuring light. It comes with a sensor that is able to convert light energy into an electrical charge that can generate a reading. A lux meter is usually small enough to be a hand-held device that is easy to move from place to place.
How you should use a lux meter?
It is important to get to know a lux meter before you use it. On some occasions, a number will be displayed by the meter. While on other occasions the display may be that of a graph or meter. To be sure the meter is working try moving it near to a light bulb or from a darkly lit room to a brightly lit one, and the numbers should fluctuate.
Find the light sensor on your lux meter to make sure you do not accidentally put your finger over it while you are doing the reading.
It is also a good idea to try making comparisons between different sources of artificial light from the same distance, using any convenient object to gauge the space. The precise distance is of less importance than just ensuring the distance is kept constant. This allows you to use the lux meter to see the difference between a light bulb and a flashlight, a computer screen and a TV screen, and to find out which light source in your workplace emits the most and the least amount of light.
You may also want to try measuring the levels of ambient light in different locations. Try turning off all artificial light sources and comparing the levels of light outside with that inside. You might also want to test the difference between a room that has the window coverings open versus one that has them closed or to find out which room in your workplace gets the most natural light.
A standard lux meter is perfect for use in areas that feature incandescent lighting and may also be used for fluorescent lighting with some caveats. They are ideal devices with which to check the lighting in the majority of workplaces.