Light intensity is measured to maintain visual comfort during work activities. We can all imagine how uncomfortable it is to read in a dim room. That is why lighting intensity in workplaces, but also on pavements and roadways, is regulated by laws, decrees and technical standards - and there are not a few of them. The expert needs to be familiar with regulations ranging from the Labour Code to the Ministry of Health's hygiene limits (e.g. in schools and nurseries) to, for example, the lighting of surface quarries or, conversely, residential buildings) to the set of standards CSN EN 12 464, which address intensity values for specific workplaces.
The requirements for lighting intensity are usually already addressed at the project documentation stage, where the technical requirements are considered in the lighting design and the appropriate luminaires are proposed. This is why so-called isolux plans are part of the project documentation, showing what the expected values are. Our technical inspection then ideally just performs a control measurement of the network of points in the required space.
The measurement is performed with a so-called luxmeter - a device that is equipped with a photodiode that acts as a sensing element. The output of the instrument is a clear display from which a numerical value in lux is directly read.