In ancient times, light was perceived by people asa phenomenon that depended on the will of higher beings ... Today, it's no secret to anyone how you can control this radiation, what is its essence, how to calculate artificial lighting.
The lack of light rays leads toa significant decrease in working capacity, deterioration of well-being and a decrease in mood. In connection with this important point is the correct, with the hygienic requirements, the placement and connection of lighting devices. For enterprises, it will be advantageous to purchase energy-saving equipment for both internal premises and for the territory.
Lighting characteristics
In the wavelength range of 380-780 nm, the electromagnetic radiation of the optical spectrum becomes visible. It can be characterized by the following values:
1. Luminous flux (this is part of the optical radiation perceived by man as light). The unit of measurement is the lumen. In the calculations it is denoted as F.
2. The intensity of light (this is the density of the light flux in space, lying in the direction of the axis of the solid angle). Denoted as I,
3. Corner angle (this is part of the space that is located inside the conical surface). It is measured in steradians. Denoted in the calculations of W.
4. Illuminance shows the value of the surface density of the light flux. Its unit is luxury, and is denoted by E.
5. Brightness is the surface density of the surface light intensity that lies in a given direction. This flow is measured in candelas per square meter and is denoted by L.
6. The indicator of glare (P) is a criterion for the dazzling action of light devices.
7. The criterion of pulsation of illumination (Kp), measured in percent, serves to estimate the relative depth of the oscillations of illumination.
8. The discomfort rate (M) is used as a criterion for assessing uncomfortable brilliance, which causes a feeling of rubbing in the eyes when the bright spot is not uniformly located in the field of view.
Measuring instruments
To determine the illumination,various luxmeters. For example, the device "Yu-116" allows you to calculate this parameter, created by an incandescent lamp and natural light. Luxmeter is used to control lighting in agriculture, transport, industry and other areas.
To measure other values, for example, brightness,the pulsation coefficient, analog-digital devices are used. An example of them is the pulsometer-luxmeter ARGUS-07. The principle of its action is in converting the light flux, which is created by extended objects, into an electrical continuous signal proportional to the illumination. Further, it is converted into a digital code displayed on the electronic scoreboard.
Types of lighting in production
If the room is lit only by lamps,floor lamps, lamps, that is, artificial light, then this lighting is called artificial. It is necessary to create comfortable working conditions, normal operation of buildings and territories. It can be divided into the following types:
- Working.
- Security.
- Emergency.
- The duty officer.
The first is used to illuminate offices, placesperformance of work outside the building. The second and fourth type of lighting is switched on during non-working hours, and the third one allocates evacuation outputs, various safe moments. Artificial lighting can be common, in which the lamps are placed evenly in the upper area of the office, or combined. In the second case, local lighting is added to the total, which is created by lamps located near the workplace.
The next type of industrial lightingis natural. Here, too, there are several types: side, top, combined. The first is when the sunlight penetrates the room through the light apertures in the outer walls. At the second, the light passes through the openings in the walls in the places of the height difference of the building or through the lanterns. The third type combines top and side lighting. This type of lighting is especially necessary in rooms with the constant presence of a large number of people.
Combined lighting is a combination ofnatural and artificial. It is used in special cases when the first to third categories are performed, if space-planning solutions for construction are required or when the feasibility study is confirmed by calculations.
Norms of types of illumination
If you select the values of the parameters you needTo rely on the SNiP "Natural and artificial lighting". In this case, the illumination of the premises is regulated by its minimum permitted level, based on the characteristics and type of visual work performed (RR). There are three types of SP:
- The first includes activities in which you do not need to use optical instruments. The object of discrimination in this case can be at different distances from the eyes.
- The second permits the use of optical instruments when performing work. The reason lies in the very small size of the object under consideration, which is not perceived by the eye.
- The third includes works in which it is necessary to perceive information from screens. This type of special requirements apply to the organization of lighting.
With the consistency of the SNiP "Natural andartificial lighting "can be identified the following characteristics of visual works without the use of optics: discharge, sub-division. The first is formed in connection with the size of the object of discrimination, and the second - from the combination of contrast and lightness of the object of discrimination with the background. For each characteristic, the illumination, the illumination index, the ripple coefficient and its methods for calculating artificial illumination are normalized.
If the lighting in the room is natural orcombined, then for the discharge of the SP the coefficient of natural illumination is given. It is the ratio of natural light to the set value of the external horizontal illuminance, which is created by the light of the open sky.
When natural light is lateral andone-sided, then a minimum value of KEO arises at a point that is located at the intersection of the vertical plane of the section of the room and the conditioned functional surface at a distance of 1 m from the wall, beyond all located from the light apertures. If the lighting is top or combined, then the average value of the coefficient at points located at the intersection of the vertical plane of the section of the room and the working surface is taken into account.
Calculation of artificial lighting
При определении системы освещения необходимо consider the economy of the combined light system, as well as its hygiene (uniformity and brightness of the light flux). When equipment in the office is uneven, localized lighting is used. The definition of the type of luminaire must be approached in accordance with the rules for the dispersion of brightness in the field of view of workers, and also depending on the state of the air environment.
For a clearer distribution of light, alighting scheme. It can be of several types: simple (connection of a small number of luminaires connected to one switch), selector connection (connection of two independent groups of light sources that are monitored at one point), bidirectional (switching on and off from two points), switching switches in two directions, and one - on one direction).
Calculation of shop lighting should consider the followingparameters: determination of the type of light sources and luminaires, their calculation and competent distribution in space, determination of their power and power scheme. In addition to the listed items, it is necessary to pay attention to the types of visual work, the environmental conditions, how the working equipment is located, the number of employees, emergency lighting.
Specific power method
Calculation of artificial lighting in this wayallows you to conduct a rough calculation of the lighting of the production premises with a uniform distribution of lamps. The power of one lamp is calculated by the formula:
Pl = PyS / pl
Where Py denotes the specific power of the lamp,the meaning of which is in the reference books. The specific power depends on the type and location of lamps and luminaires, the characteristics of the illuminated room, as well as the height of the suspension. The value of S indicates the floor area, and m is the number of lamps. The results are usually rounded to a higher value.
Method of light flux or utilization rate
This method calculates the productionLighting in cases where the illumination of the working surface is specified. The method does not apply to localized outdoor and local illumination if the working surfaces are not horizontal, and also when calculating the directional concentrated light flux.
Calculations are carried out according to the formula:
F = En S Z K / Nη
Where F is the light flux; En is a normalizedillumination; S is the floor area; N is the number of lamps; Z is the minimum power factor; K is the safety factor; η is the coefficient of utilization of the light beams of the lamps.
По значению светового потока отбирается lamp, which may differ from the calculated value in the range from -10 to +20 percent. If the difference is greater than the allowed limits, then the number of luminaires is regulated.
Point method
The method is used to determine the light rays.lamps in cases where reflected light is unimportant. The method is used for any arrangement of the illuminated surface and lamps. The method is based on the relationship between the dependence of surface illumination (E), which is created by a point source of light, on the distance to the surface (r), the angle of incidence of the beam (a) and the intensity of light (I):
E = I cos α / r2
The calculation of the lighting workshop, and specifically the lighting installation, includes several steps:
1. Finding the minimum normalized illumination.
2. Selecting the type of light source. Determination of the type of lamps and their placement in the shop.
3. The selection of control points with the least conventional illumination on the office plan.
4. At the control points, calculations are made on the conditional illumination. The subsequent calculation of the lighting of the production area is based on the point with the smallest conventional illumination.
5. Using reference tables to determine the coefficients of the additional light and margin.
6. Find the luminous flux of the lamps. According to the results select a standard lamp.
7. Determine the power of the lamp and the entire light installation.
An example of the calculation of lighting we give the following:in the problem, the height is h = 4 m, the safety factor is k = 1.5, the incremental illumination factor is u = 1.2, the normalized illumination is Emin = 75 lx. It is necessary to determine the lighting with working surfaces near the walls of the DFC lamps.
Since in the lamps of this type deeplight distribution, for them λ = 1. The distance between the light installations will be 4 m, and from the outermost fixtures to the walls - 1 m. Place on the plan control points A, B (with the least illumination) and calculate the distance from them to the projections of the nearest fixtures (d). The next item will be the definition of conditional illumination and finding the point with the lowest illumination. According to calculate the value of the luminous flux of the lamp, its difference with the standard value, and also find the lighting.
Calculation of total illumination when working with computers
The room must be artificial andnatural lighting, with a coefficient KEO not lower than 1.2%. It is necessary that the working surface with computers be oriented sideways to the light openings for the penetration of natural light. The calculation of the artificial lighting of the room is carried out relative to the system of uniform uniform incidence of light. Direct gloss is limited from light sources (the brightness of windows, lamps and other luminous surfaces is not more than 200 cd / m2 ), and the reflected one is adjusted due to the correct choice of lamps and positions of functional places depending on the basis of the light (the brightness of glare on the screen is not more than 40 cd / m2 ).
With artificial light as sourcesLight need to use fluorescent and compact fluorescent lamps. If the premises are industrial or public in nature, then metal halide lamps can be used. Luminaires should be with shielding grilles and diffusers.
Street Lighting Solutions
Street lighting has the important task of combiningexternal plots as a whole, plays the role of a helper of security and orientation in space, and also makes an aesthetic touch in the decoration of cities. Lighting equipment for this type of lighting must be selected depending on the features and status of objects. They can be activated automatically or with the help of a dispatcher. There are several types of street lighting:
- Flooding The essence of the method is in the installation and targeting of floodlights. It is used for illumination for security purposes of adjacent territories.
- General This method includes the uniform distribution of luminaires of the same type. It is ideal for illuminating tracks, parks, areas where people and cars move.
- Marking.With this type of street lighting, lamps are arranged along selected lines and shapes. It is used to create visual contours, emphasize relief, highlighting the direction of roads and pedestrian roads.
