What is the use of a goniophotometer?

A goniophotometer is a device used to determine the amount of light emitted by an item at various angles. The usage of goniophotometers has increased in recent years due to the advent of LED light sources, which are predominantly directed light sources with a non-homogeneous spatial distribution of light. If a light source’s distribution of light is homogenous, it is referred to as a Lambertian source. Due to stringent restrictions, the spatial distribution of light is critical to the design of vehicle lighting.

What is a goniophotometer?
When a light turns on, it produces light. This light has a distinct hue, a distinct “strength,” and may vary in intensity depending on the angle at which it is seen. These characteristics are classified according to wavelength, phase, frequency, and amplitude. The goniophotometer is capable of determining the quantity of luminous flux produced by a light source and the distribution of luminous intensity. Additionally, some instruments can determine the color temperature distribution and color homogeneity.

The goniophotometer has grown in popularity as LED lighting technology advances. LEDs have a natural propensity to guide light in a certain direction, referred to as a Lambertian source. A standard light bulb distributes light in a very uniform radial distribution, emitting light in all directions at about the same intensity. The goniophotometer is used to identify the kind of light emitted by a headlight to comply with standards within the automobile sector.

Main uses:
Luminous flux
The luminous flux is the whole quantity of light released by a source of light without concern for direction. For instance, a laser produces a tremendous quantity of light flux in a single tiny area but little to no luminous flux in any other direction.

A traditional lightbulb is very different in that it emits the same amount of luminous flux in all directions. The combined output of both sources may remain similar. The laser concentrates it in a single point, while the conventional light bulb disperses it across a wider region.

Luminous intensity
The luminous intensity of a light source is the quantity of light emitted at a certain angle and distance. A directed light source may provide an enormous amount of luminous intensity when seen from a certain angle, yet practically none when viewed from a slightly another angle. Therefore, LISUN has made the finest goniophotometer.

In this instance, the laser mentioned above would have a high light intensity in a single tiny area but little to none in any other direction. The old light bulb’s luminous intensity would be very low, but it would be uniform in all directions.

Color temperature distribution
Color temperature is dependent on the kind of light. These values ​​vary from 1000 kelvin (a good amount of red) to 27000 kelvin (very blue-ish). For comparison, temperatures between 2500 and 5000 kelvin are often referred to as “warm white,” whereas temperatures between 5000 and 7500 kelvin are “cold white.”

Uniformity of color
When light is measured from various angles and distances, its characteristics may vary. A high degree of color uniformity indicates that the color temperature is uniformly distributed across all angles. In contrast, a low degree of color uniformity indicates that the color temperature varies significantly across all angles.

Various types of goniophotometers are available
Goniophotometers are usually classified into three types:
Type A – LISUN LSG-1950 Goniophotometer for Automotive and Signal Lamps
This type of goniophotometer only from a fixed horizontal axis can measurements be taken.

Type B – LISUN LSG-1890B High Precision Rotation Luminaire Goniophotometer
This goniophotometer measures from the fixed vertical axis.

Type C – LISUN LSG-6000 LM-79 Moving Detector Goniophotometer (Mirror Type C)
This kind of goniophotometer measures the vertical and horizontal axes simultaneously.

 

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