To determine the useful life of the lighting (irradiation) lamps using light-decay curves (Radiant) flow in the combustion process. In order to reduce the time trials mean burning time of lamps is defined as a burning lamp, which occupies a middle position in the order of a blown bulbs this group, such as the lamp burned-sixth, with 11 tubes in the group. Among the many different types of test tubes in, terms of service and stability we note the bench and running. Posters are held in strict installed. and controlled conditions, performance – in order to detect or monitor the effect of individual factors and environmental conditions (stability and resistance to mechanical and climatic influences, stress network, switching frequency, the cooling conditions, the provisions of combustion, etc.) on the parameters of tubes and their change in the combustion process.

An important indicator of reliability is also the probability of failure of the lamp within a given time, which is often governed by a minimum duration of combustion. The fitness of the source to the conditions of the installation by the following factors: the dividend stream of the source radiation, ie, the possibility of manufacture of tubes for various power – a necessary condition for a rational pattern of distribution of lighting systems in space radiation and the size of the luminous body, on which the the possibility of rational distribution of the light source to install and rational redistribution of the radiation flux in space, the degree of adaptation of the source to the normal elements of lighting installation allows use of standard elements, adaptation to the regime of standard power supplies universal light source, allowing its use in many areas of lighting hygienic, which is determined by the requirements relating to hygiene of view, as well as general occupational health and safety agencies of Hygiene makes claims to the stability in time of the luminous flux distribution energy spectrum and density or intensity of the radiation. General hygiene requires a security light sources in use, as well as the absence of radiation, gases or other emissions during operation of the source is harmful acting on the body. Economy. In the development of light sources, especially mass application, you must seek the highest possible all operating parameters, including the economy. The parameters of the light source and install a number of interconnected relationships, and usually can not be achieved simultaneously improving all the necessary parameters and the light source and lighting installation. For create the most advanced lighting systems should be in each case to develop an optimality criterion, taking into account the restrictions imposed, allowing quantitatively compare the fitness different light sources in certain cases, to choose the best conditions for its operation.

For light sources, the massive use of such generalizing economic criteria can serve as cost of operation, referred to one lumen hour, or other similar reduced value, and, more generally, given the costs. Given cost is called the cost of operation of the plant per unit produced product. Cost is the cost of electricity supply installation, the cost of changing lamps, replacement cost depreciation and ongoing maintenance costs of parts and installation. The optimal option would be to lowest cost of operation per lumen hour for other conditions being equal (eg, lighting, lighting quality, etc.) or, more generally, a variant with the lowest cost given