• # BLOG

## What is the Efficiency Factor (Luminous Efficiency)?

Nowadays, it is impossible to imagine a life without light. Although Light is among the indispensable parts of our lives, we do not know much about the terms related to "Light". One of the terms, which is actually quite important when we look at it, but which many people do not know, is known as Luminous Efficiency (Efficiency Factor).

Activity Factor; Also known as Luminous Efficiency or Luminous Efficiency. Luminous efficiency is a physical quantity used to show how good the visible light emitted by a light source is. However, questions about luminous efficiency are not limited to the "What is" question.

In this article, we will answer the questions of What is the Luminous Efficiency Formula, How to Calculate and How to Measure. We will also talk about the Factors Affecting Luminous Efficiency.

## What is the Luminous Efficiency Formula? How is it calculated?

What is the Luminous Efficiency Formula? How is it calculated?

Luminous Efficiency (Efficiency Factor) = Luminous Flux (Lumen-lm) / Power (Watt-W).

The calculation of the luminous efficiency is quite simple. For example; If the luminous flux of a 10 W light source is 1000 lumens, the luminous efficiency of this source is calculated from 1000 / 10 to 100 Lumen / Watt.

## Factors Affecting Luminous Efficiency

Luminous efficiency is affected by various factors as it is a physical quantity. The type of lamp used in the lighting fixture is very important. Because; The type of lamp used in the luminaire directly affects the consumed electrical power and luminous flux. In other words, lamp types such as fluorescent lamp, halogen lamp, LED or incandescent lamp used in lighting fixtures directly affect the luminous efficiency.

Apart from the lamp used in the luminaire, parts such as the diffuser, lens or reflector used in the luminaire are important in the control of the light, so they also affect the efficiency.

## How is Luminous Efficiency Measured?

There are different ways of measuring luminous efficiency. One of them is measuring instruments known as integrated spheres. The integrated sphere serves to measure the total light scattered from the luminaire, namely the luminous flux, in lumens. After obtaining the lumen value, the maximum power consumed by the light source is calculated. In order to calculate the power, the maximum current is measured from the cable where the energy is fed. But here the current is measured in Amps. By making the necessary calculations, the maximum power is found in Watts. Then, the obtained values are replaced in the efficiency factor formula and the measurement is made.

Another and easy way is the information provided by the luminaire manufacturer to the user. The luminaire manufacturer gives the user maximum power consumption (Watt) and luminous flux (lumen) values. In this way, the luminous efficiency can be calculated using the luminous efficiency formula.