You will need

- calculator.

Instruction

1

According to the definition, the light in one Suite create a light source with a luminous flux of one lumen, if it is uniformly lights the surface area of one square meter. Consequently, the transfer lumen in the suites, use the formula:

Klux = Lumen / Km2

To put the suites in lumens, use the formula:

Lumen = Clux * Km2

where:

Klux – illumination (number of Suite);

Lumen – the luminous flux value (lumen output);

Km2 - illuminated area (in square meters).

Klux = Lumen / Km2

To put the suites in lumens, use the formula:

Lumen = Clux * Km2

where:

Klux – illumination (number of Suite);

Lumen – the luminous flux value (lumen output);

Km2 - illuminated area (in square meters).

2

In the calculations, keep in mind that the lighting must be uniform. In practice, this means that all points of the surface should be equidistant from the light source. At the same time, the light should hit all the surface areas under the same angle. Also note that the surface should fall the whole of the light source luminous flux.

3

If the light source is close in form to a point, uniform lighting can only be achieved on the inner surface of the sphere. However, if the lamp is far enough from the illuminated surface, and the surface is relatively smooth and has a small area, the illumination can be considered almost uniform. "Vivid" example of such a light source can be considered the sun, which due to the huge distance is nearly a point source of light.

4

Example: In the center of a cubic room height of 10 meters, and is a incandescent bulb of 100 watts.

Question: what will be the illumination of the ceiling of the room?

Solution: the incandescent bulb 100 Watt creates a luminous flux is approximately equal to 1300 lumens (LM). This flow is distributed into six equal surfaces (walls, floor, and ceiling) with a total area of 600 m2. Consequently their illumination (average) amount: 1300 / 600 = 2,167 Cf. Accordingly, the average illumination of the ceiling will also be equal 2,167 LK.

Question: what will be the illumination of the ceiling of the room?

Solution: the incandescent bulb 100 Watt creates a luminous flux is approximately equal to 1300 lumens (LM). This flow is distributed into six equal surfaces (walls, floor, and ceiling) with a total area of 600 m2. Consequently their illumination (average) amount: 1300 / 600 = 2,167 Cf. Accordingly, the average illumination of the ceiling will also be equal 2,167 LK.

5

For the solution of the inverse problem (determination of the luminous flux at a given illumination and surface area), simply multiply the illuminance of the area.

6

In practice, however, the amount of light generated by the light source, so is not calculated, but measured using special instruments – a spherical photometers and photometric goniometers. But since most light sources have a standard characteristics, for practical calculations use the following table:

Incandescent lamp 60 W (220 V) – 500 LM.

Incandescent 100 W (220 V) – 1300 LM.

Fluorescent lamp 26 W (220 V) - 1600 LM.

Sodium-vapor lamp (street) - 10000...20000 LM.

Sodium low pressure lamps - 200 Lumens/watt.

LEDs – about 100 LM/W.

The Sun Is 3.8 * 10^28 LM.

Incandescent lamp 60 W (220 V) – 500 LM.

Incandescent 100 W (220 V) – 1300 LM.

Fluorescent lamp 26 W (220 V) - 1600 LM.

Sodium-vapor lamp (street) - 10000...20000 LM.

Sodium low pressure lamps - 200 Lumens/watt.

LEDs – about 100 LM/W.

The Sun Is 3.8 * 10^28 LM.

7

LM/W is the efficiency indicator of the light source. For example, the led 5 watt will provide a luminous flux of 500 LM. Which corresponds to the incandescent bulb that consumes 60 watts!

# Advice 2: How to translate W/in the hour W

When calculating the amount of electricity consumed, it is customary to use the term "kilowatt-

**hours**". This value is the actual power consumption device power N kilowatt a number of hours X.Instruction

1

Start to understand what kind of value you need to take into consideration. The fact that very often in the calculation of electricity the concept of kilowatt-

**hours**and kilowatts are confusing. Although kW is power (that is, the amount consumed by the device of energy) and kilowatt-hour is the amount of time consumed per hour.2

Please note that the data on energy consumed on the electric counter indicated in kilowatts. To convert them into watts, multiply the number of kilowatt one thousand. Thus, 1 kilowatt * 1000 = 1000 watts.

3

As watt-

**hours**or kilowatt-**hours**is the amount of watts for a certain period of time, for calculations you must know for what period of time to get the figure. Divide the number of watt-hours by the number of hours for which the calculation is performed.4

For example, you know that in the past month (30 days) consumption of electricity metering devices is 72 kilowatt/hours. Multiply this figure by a thousand. To obtain the number of watts. 68,4*1000=68400 watts/hour. Now divide the resulting figure by 720. That's the number of hours in one month (30*24=720). 68400/720=95 watts. It turns out that in the course of a month constantly burning one light bulb with a power of 95 watts.

5

Remember that the data remain approximate average character, if you produce a General calculation. It is impossible to distinguish one particular appliance. This formula does not take into account the loss of energy. To calculate power watts for a single device you need to connect it to the network in a single copy, included leaving within the hour. The resulting figure will be the desired value. For example, if the network was enabled iron. Potrebu one hour 1500 watt/hour, power consumption of this device would be exactly 1500 watts.