Illumination measurement range: 1.0 ÷ 200000 lux

Limit of permissible basic relative error: 6%

The peculiarity of the lux meter is that it is the cheapest lux meter that can be bought with verification and from 1 lux!

Illumination measurement range 1.0 ÷ 50,000 lux

Basic relative error of illumination measurement (no more) ± 2.0%

The peculiarity of the lux meter is that the lux meter is a working standard of the 1st category. The device is intended for verification (calibration) of working illumination measuring instruments.

Illumination range: 1 ÷ 200000 Lux

Measurement error: 10%

Measuring range 0 ÷ 99.999 Lux

Accuracy ± 3 Lux Or 3% of reading. meaning (compared to the standard)

Resolution 1 Lux (0 ÷ 19.999 Lux); 10 Lux (in remaining range)

The peculiarity of the light meter is German quality and reliability! But the certified measurement range in the Russian Federation is 100 - 99,990 lux!

Measuring range 0 ÷ 100000 Lux

Resolution 1 Lux (0 ÷ 32000 Lux); 10 Lux (0 ÷ +100000 Lux)

The human eye is not able to determine the absolute intensity of light, since it is endowed with the ability to adapt to lighting. In addition, the human eye better perceives waves of such lengths that are not very suitable for plants. A special device can help measure illumination - lux meter.

Rice. 4.

A lux meter is a portable device, which is one of the types of photometers that is used to measure illumination.

The simplest lux meter consists of a photocell that converts light energy into electrical energy. Its operation is based on the principle of the photoelectric effect: when light rays hit semiconductor photocells, they transfer their energy to electrons. A stream of light hitting a photocell releases a stream of electrons in the body of the semiconductor. Thanks to this, the photocell begins to conduct electric current. The magnitude of this current is directly proportional to the illumination of the photocell. It is reflected on the scale. In analog lux meters, the scale is graduated in lux, the result is determined by the deflection of the needle.

Rice. 5.

Now analog (Fig. 4) are being replaced by digital (Fig. 5) devices for measuring illumination. In them, the measurement result is displayed on a liquid crystal display. The measuring part in many of them is located in a separate housing and is connected to the device by a flexible wire. This allows measurements to be taken in hard-to-reach places. Thanks to a set of light filters, the limits of its measurements can be adjusted. In this case, the instrument readings must be multiplied by certain coefficients.

Light measurement

When assessing lighting, several parameters are used (luminous intensity, brightness, etc.), but the main indicator is illumination.

Rice. 6.

IN International system units, the measure of illumination is 1 lux.

Lux is equal to the illumination of a surface with an area of ​​1 m 2, with a luminous flux of radiation incident on it equal to 1 lumen (Fig. 6).

Illumination measurements are carried out in accordance with GOST Interstate Standard "Buildings and structures. Methods for measuring illumination." This standard establishes methods for determining the minimum, average and cylindrical illumination, the coefficient of natural illumination in the premises of buildings, structures and workplaces, the minimum illumination in places where work is carried out outside buildings, the average illumination of streets, roads, squares and tunnels.

To measure illumination, you should use lux meters with measuring radiation converters that have a spectral error of no more than 10%. Luxmeters must have certificates of metrological certification and verification. The device must always be in horizontal position. It is installed at the required points.

Operating procedure:

It is necessary to install the lux meter on the surface whose illumination is being measured. The plane of the photosensitive element of the sensor must be parallel to the surface illuminated by the light source. After this, readings are taken from the scale of an analog device or a digital display - this will be the illumination of this surface in lux.

Measurements are carried out separately for artificial and natural lighting. In this case, you need to make sure that no shadow falls on the device, and that there is no source nearby electromagnetic radiation. This will interfere with the results. After all the necessary illumination measurements have been made, based on the results obtained, using special formulas, the required parameters, and an overall assessment is made. That is, the obtained parameters are compared with the standard, and a conclusion is made about whether the illumination of a given room or area is sufficient.

A separate protocol is filled out for each type of measurement in each room or section of the street. An assessment protocol is issued both for each room or territory, and for the entire facility. This is required by GOST. Illumination Measurement.

Illumination must be measured at least once a month, and in systems with combined lighting, illumination should be measured separately: from local lighting, from general lighting lamps and from the entire system as a whole.

Before using the device to measure the illumination of artificial lighting, it is necessary to clean the lamps and replace all non-working lamps. Measuring illumination with special devices can also be used without preliminary preparation of the corresponding lighting installation, however, these nuances must be recorded when recording the measurement results on a medium.

Measuring the coefficient of natural illumination (NLC) with lux meters is carried out in rooms that are previously cleared of equipment and furniture, also not shaded by trees and landscaping, with cleaned and serviceable translucent fillings in the light openings. But when using devices for measuring illumination in rooms with furniture, with faulty or uncleaned translucent fillings, or when shaded by trees, the data must be taken into account and recorded in the measurement results.

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Light intensity measurement

The brightness of light or luminous flux is measured in lumens (lm, lm) and is denoted by the letter F. This quantity is difficult to describe physically; it is much easier to imagine that the luminous flux F falls on any surface and illuminates it.
The illumination of such a surface is measured in lux (lx) and is designated by the letter E.

This means that 1 lux is equal to 1 lumen divided by 1 square meter.
Examples of lighting in nature:
Full moon night - illumination of the earth = 1 lux.
Autumn cloudy day - ground illumination = 100 lux.
A clear sunny day in the shade - ground illumination = 10,000-25,000 lux.
Under direct sun - illumination of the earth = 32000-130000 lux.

Electric lighting

Room lighting can be natural or artificial.
Natural light This is the lighting of a room through windows, ceilings and other transparent building structures.
Since this site is dedicated to power supply, we will dwell in more detail on artificial lighting, which modern world carried out using electricity. (in the Middle Ages, gas lamps, liquid fuel lamps, candles and torches predominated)

Artificial lighting is divided into:

1. Working (general) lighting- this is the main lighting that provides normal conditions for a person to stay in the room. Normal means the living conditions of a person, under which he does not strain his eyesight in order to perform any action for which this room is intended.
Simply put, if you come to a supermarket and are trying to read small text on a product package, then you need illumination of at least 300 lux, which is what is provided for in the building codes of the Russian Federation. A document detailing lighting standards is called SNiP 23-05-95.

It is especially important to take into account lighting standards in rooms where people perform intense visual work for a long time. In workplaces with this type of work, it is necessary to provide additional local lighting.

Light sources in modern lamps are three main types of lamps:

Incandescent lamps are the simplest device that transforms electrical energy into light by conventional heating of a tungsten filament.

Gas discharge lamps - this category includes lamps based on light produced by an electrical discharge in gas or metal vapor. These lamps occupy a predominant position among lighting devices. The types of such lamps are diverse: these are “energy-saving” lamps, actively pushed lately to the masses, and mercury lamps DRL type used in spotlights and lamps street lighting(sodium DNAT) and many others.

LED lamps- new and promising development of lighting devices associated with the advent of ultra-bright LEDs.

It's easy to get lost in such diversity. Let's try to compare such different light sources. The main parameter will be the efficiency of the light source, that is, how much light it produces by consuming 1 Watt of electricity (lm/W).

The table shows that the incandescent lamp is hopelessly inferior to other lighting sources.
However, do not forget about the quality of the light flux - it is considered optimal for the perception of the human eye sunlight. An incandescent lamp produces a spectrum of light that is closest to that of the sun.

2. Emergency lighting- this is lighting that is designed to safely complete production process(safety lighting) or evacuate from a building or premises (evacuation lighting) if the main lighting is turned off. The main difference of this lighting is the increased reliability of power supply, ensured by the first category of power supply, the introduction of additional sources of electricity (batteries) and other measures.

3. Security and emergency lighting No comments are needed, since everything is clear from the title.

Lighting calculation

The result of the lighting calculation is an EO brand project, which indicates the installation locations of lamps, lighting supply networks and calculated lighting values ​​for each room.

There are several ways to calculate lighting manually:

Luminous flux utilization factor method:
The essence of the method is to calculate the coefficient for each room, based on the basic parameters of the room and reflective properties finishing materials. The disadvantages of this calculation method are the high complexity of the calculation and low accuracy. This method is used to calculate internal lighting.

The second method is the point method:
According to this technique, illumination is determined at each point of the calculated surface, relative to each light source. It is not difficult to guess that labor intensity this method just huge! Accuracy is directly dependent on the conscientiousness of the engineer conducting the calculation.

We live in the 21st century, when almost all labor-intensive operations are performed by machines. That's why in the best possible way Calculation of lighting is a calculation using a computer.

The German company DIAL kindly provides everyone with free program for calculating DIALux lighting. A program based on lighting technical data of lamps and three-dimensional model object calculates illumination and other parameters.

High quality, accurate and fast.

P.S. By neglecting lighting calculations, you risk getting into one of the following situations:

The building has been constructed, the finishing has been completed, and the lighting in the premises is below the requirements of sanitary standards (upon commissioning preschool institutions, schools, administrative buildings, healthcare institutions, such measurements are required). The cost of remodeling will cost much more than any project.

Illumination of the courtyard area of ​​a small residential complex, exceeding the norm by 50 lux, will “gobble up” an extra ten kilowatt-hours of electricity per night.

Currently there are technical capabilities for measuring almost all known physical quantities. This fully applies to lighting engineering issues, since artificial light is widely used in everyday life. It may be too dim, with a high ripple factor, causing negative influence on vision and general health of a person. In order to promptly avoid negative consequences, a special device for measuring illumination is used - a lux meter.

Using a lux meter, it is possible to accurately determine the light characteristics and adjust the necessary parameters to the specified values. Therefore, you need to know not only general device, but also the operating principle of this device, so that all measurements are carried out correctly and accurately.

Luminous flux and illumination

Before talking about measurements, it is first necessary to clarify the basic concepts of lighting technical quantities. Quite often there are discrepancies in terminology when illumination is identified with.

These are completely different quantities, although related to each other in a certain way. For example, the luminous flux characterizes a particular lighting element and relates specifically to this light source. The unit of measurement is the lumen, which represents the intensity of light with a power of one candela located within a solid angle of 1 steradian.

Illumination, in turn, is formed from the first quantity, since it is the luminous flux acting on a unit area. To determine this value, there is a special unit - lux, obtained as a result of illumination with a luminous flux of 1 lumen of any surface with an area of ​​\u200b\u200b1 m2. Thus, illuminance is not directly related to the light source, but is related to the environment.

Unlike the luminous flux, which is a constant value, the illumination parameters in different points premises will differ depending on certain local conditions:

• The number of lamps located near the places where measurements are taken.
• Light pressure produced by all lighting fixtures.
• Distance to lighting devices.
• The ability of surfaces located in a room to reflect light.

To measure illumination, there is a special measuring device - a lux meter, which is widely used in everyday life and in production.

Where is a lux meter used?

The Greek word lux means light, so a device that measures illuminance is called a luxmeter. This measuring device is used both indoors and outdoors. Why is this device needed and why measure illumination at all?

Scientists have long proven that the effect of weak or, conversely, too strong light, negatively affects the brain, causing negative reaction and other organs. Insufficient lighting in the premises leads to a decrease in performance, drowsiness appears, and attention is distracted. Too bright lighting has a stimulating effect on nervous system. At work, and in everyday life, this state of the body often becomes the cause of domestic injuries and accidents.

In this regard, among many occupational safety measures important role Checking the illumination of workplaces plays a role. There is a special GOST R 55710-2013 that defines standards for different types production and other premises in suites (lux). For example, the illumination indicator for offices is on average 200-300 lux.

Lux meters are widely used in other areas. With their help, the required level of illumination for plants grown in greenhouse conditions is measured, controlled and maintained. The fact is that the degree of brightness of light has a direct impact on photosynthesis, through which plants produce nutrients from carbon in the air. The proper growth and development of crops is influenced by lighting and temperature regime. For most plants, moderate lighting is considered the most optimal conditions.

Operating principle

Every lux meter uses a photocell. It is made in the form of a semiconductor device in which energy is transferred from light quanta to electrons, which leads to the appearance of an electric current. The degree of illumination at the location of the photodetector is proportional to the strength of this current.

The design of the lux meter is supplemented various types indicators. When using a digital element, the electric current is converted by an optical-electronic converter and displayed as readings on the display. In another case, the current conversion is carried out using, which actuates the analogue pointer. Structurally, the indicator and photocell are connected to each other by a common conductor and are located in the same housing.

In some models, these parts may be placed separately from each other. A monoblock device is lighter in weight and is considered more convenient, so it is used when quick and efficient lighting measurements are required. For hard-to-reach places, lux meters with a photosensor connected separately to the main structure are best suited.

Characteristics of testo 540 and 545

Among the many measuring devices You should pay attention to the German-made “testo 540” digital lux meter model. Thanks to its qualities and technical specifications, this device for measuring illumination has won the recognition of many Russian users.

It is made in the form of a monoblock design with a photocell integrated directly into the body. The absence of a connecting wire makes it more convenient to use, since one hand is enough to take measurements.

The configuration and dimensions of the lux meter are comparable to mobile phone. All readings are displayed on the liquid crystal display, and the entire keyboard consists of three buttons.

1. The first button is used to turn it on and off;
2. The second is for selecting the system and units of measurement;
3. The third is for saving the results obtained.

Illumination measurements can be performed in the range from 0 to 100 thousand lux. The device is very easy to use and can be used in almost any area of ​​daily life.

A professional meter is considered a more advanced device - the testo 545 lux meter, in which the light receiver and the electronic unit are located separately, connected by a conductor. It differs significantly a large number functions and allows you to use different methods measurements Up to 99 measurement locations and up to 3000 results obtained can be stored in memory. When connected to a computer, it becomes possible to create a three-dimensional illumination graph for a single room, and print the received information on a printer.

How to measure illumination using the device

Before taking measurements, you need to set up the device. For this purpose, the following actions are performed:

• The attachments installed on the photodetector must have maximum light absorption. After this, you need to turn on the right button, corresponding to the maximum illumination of up to 100 thousand lux. If the indicator or arrow does not respond, it turns on left button, configured for illumination up to 30 thousand lux.
• If there is no further reaction, the photodetector filter should be replaced with a more transparent one, and then switch on again in the same sequence. Filter replacement must continue until the indicator starts to turn on. In all cases, excessive illumination of the photosensor must be avoided, as this may affect the accuracy of the obtained measurement results.
• Luxmeters with a spectral error of more than 10% are allowed for measurements, if a correction factor related to the spectral composition of a particular light source is used.
• Each lux meter must be certified to obtain a metrological certificate.

Before measuring illumination, all burnt-out lamps must be replaced and the lamps themselves cleaned. All furniture and equipment must be removed from the premises, glass in window openings must be washed clean. Preliminarily, control points are marked on the floor plan in the area of ​​the workplaces, which indicate the placed lamps. Checkpoints for emergency lighting are marked in accordance with special standards.

Direct illumination measurement is performed as follows:

• The devices are installed at the measuring point in a horizontal position. When measuring the illumination of a workplace, the photosensor is directed towards the light source.
• Next, the device is switched to measurement mode using the desired button.
• The desired result will appear on the display.