Effective lighting for forestry

Providing lighting for forestry equipment in the most northern parts of the world is very challenging, but it is an area in which TYRI excels.

The main reasons for the challenges are the seasonal variations. For example, in Autumn when the days are short and there is no snow on the ground, the need for high colour temperature is great; ideally, as close to the colour temperature of the sun. This is due to the ground “eating up” all the light; the average reflection of light over the field of view is very low, in the range of 5-10%. The reflection is especially low in the blue portion of the spectrum which must be compensated by cold light with a blue shifted spectrum.

In contrast, during winter months, snow covered ground creates intense glare with the average reflection over the field of view being in the range of 70-90%. Ideally, lighting that has a lower colour temperature as well as a lower illumination level is required to reduce the reflection from the snow. This would especially be needed when a tree is harvested, due to the risk of snow falling from the canopy of the felled tree and the subsequent cloud causing extreme glare for the operator of the machine.

In a perfect world you would like to be able to switch the colour temperature according to the seasons; warmer light combined with less illuminance when there is snow, and colder light providing considerably higher illuminance levels when there is no snow on the ground.

These features are available with the TYRI INTELLilight. This system allows you to adjust both the colour temperature range, from 2800 K (halogen) to 6500 K (sun light), as well as the illumination level between 0-100%.

Additionally, you are also able to dim any individual lamp regardless of the light next to it, from 0% to 100% and add a light luminance sensor that reacts to glare and dim lights automatically.

This is a very effective solution for machines with multiple operators as you can personalise your settings. If we take a son and a father as an example, the father needs about twice as much light as the son, due to the ageing effects of the whole eye. The eye lens starts deteriorating as early as 40 resulting in higher absorption of light as well as increased light scattering due to inception of cataract.  Lens cataract makes the eye more sensitive to glare especially from cool light sources as the blue light scatters more easily compared with longer wavelengths. With TYRI INTELLilight it is possible to adjust the lights according to each operator’s need, then save the preferences and always have the lights working in the most effective way for you without any reprogramming between operator changeovers. This is programmed via the INTELLilight App for smartphone/tablet, alternatively it can be built into the machine using the TYRI Gateway which communicates via CAN-bus and added to the machine’s operator interface as a factory option.

The eye is a phenomenal optical system, it adapts to a wide range of illumination scenarios, but if the luminaire setup is ineffective, the operator’s eyes will tire quickly, and the productivity of the machine will decline due to fatigue of the operator.

Humans are drawn to fire and its light, however, when we look away from the fire, our vision is impaired. This is due to the fire projecting an intense light and the eye adjusting to that level. When we look away, we see nothing for a short time until the eye has readjusted to a less intense light; dark adaptation of the eye takes several minutes while adaption to brighter illumination levels take only a few seconds. This phenomena is seen with poorly lit machines, which have a high percentage of light concentrated in a small area in the field of view. The retina of the eye needs to adapt as you move your eyes, which causes eye fatigue and the operators productivity drops.

The key to lighting is uniformity; the less variation in luminance you have over the work area, the less the eyes need to adapt, and the operator maintains productivity levels.

High lumen value of lighting is less important than the uniformity of lighting over the whole field of view. You can have a very good, even lighting spread over your work area with an array of 2500 effective lumen work lights and very bad lighting with 4000 effective lumen work lights without even coverage. It’s all down to uniformity, avoiding hot spots in the field of view, and how you mount and use your lights.

When you work with TYRI to develop lighting for a machine, we do the light simulations based on your machine design. We spend a lot of time on light simulations in order to get a smooth light distribution with a uniform illumination level in the work area for the machine in question. We have the widest range of light distribution lenses for each work light model, and if you have a specific need for your machine, we will develop a customised lens for you.

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