Spectrometer takes on LED flicker problem

The cause of flicker is primarily the LED drivers used to control the light fixtures. These also regulate dimming or colour shifts in LEDs, for example. Flicker becomes significantly perceptible for humans when there is frequency overlay and interference in various light fixtures.

It is primarily lower flicker rates of up to 120Hz that have negative effects on the well-being of humans.

Depending on an individual’s level of sensitivity, these can lead to problems ranging from headaches to photosensitive epilepsy.

As far as physical terms are concerned, the term flicker is generally understood to mean changes in the luminous flux over a defined period of time.

The new GL SPECTIS 1.0 Touch FL spectrometer from GL Optic, which will be exhibited at electronica in Munich, can perform this measurement for a signal range of 0.1Hz to 12.5kHz and virtually all sources of light can be examined.

In order to characterise sources of light comprehensively and in order to compare these with one another, flicker parameters have been established and the spectrometer also has a command of these.

Among these are the mentioned flicker frequency, the flicker index and the flicker factor, which is expressed as a percentage.

The final example can be calculated using the ratio of maximum, minimum and average illumination intensity of a light fixture. For this new flicker function, the existing GL SPECTIS 1.0 Touch had a photo diode added to measure flicker.

This allows continued measurement of photometric and colorimetric data such as illumination level in addition to the new flicker parameters. Moreover, the GL SPECTIS 1.0 Touch FL also has a touch screen and a compact structure which means it is ideal for use on the go.

The spectrometer can be used during production and quality assurance assessment of LED light fixtures and while conducting lighting design and by light technicians.

This means that it is possible to overlap the frequencies of more light sources. If one would like to check the dominating frequencies which cause flicker, up to five dominant frequency shares can be determined with the spectrometer using the FFT measurement (Fast Fourier Transformation).

In the face of rising standards for quality of light and consideration of the effects on the human organism, flicker has moved into the spotlight. With the new GL SPECTIS 1.0 Touch FL from GL Optic, flicker can now be detected, determined and ultimately avoided.