If you want to buy a new lighting system for your crash test facility you normally go this way:

• You invite three companies for a tender
• From every company you mostly get quote, lighting simulation
• You order the solution that seems to be the most convincing and cancel the other

But are you sure that this is the best solution for your needs?

I can help you with planning and realizing the best lighting solution
for your crash test facility.
These are the main questions that we need to get answered:

HOW MUCH LIGHT IS NEEDED?


In sled test facilities the distance from axis of sled to lamp is typically up to 4m whereas in crash facilities the distances are beyond 4m. Longer distances require more light, but the quantity of light also depends on these HS Camera parameters:

- Desired resolution
- Desired frame rate
- Desired exposure time (shutter angle)
- Desired f-stop (depth of field)




Although there are rules-of-thumb (coming later), HS Camera test shots in the light of your chosen lamps with your chosen camera parameters are highly recommended. Then you can assess the quality of the lighting system.





HMI OR LED LIGHT?


For more than two decades Metal Halide Lamps (HMI) has been the best choice. The benefits are obvious:

- High power,
- High efficiency,
- Small number of lamps required.

Now LED lamps have arrived in the industry.
They have features which overcome some of the disadvantages of HMI light:

- LEDs emit cool light.
- LEDs have a very long life.
- The LEDs are immediately on 100%, whereas HMIs need 5 minutes after ignition to reach their full light level.

Some manufacturers in the crash test business say that their LED lamps are as bright as a 3 kW, respectively a 4 kW HMI. We tested this. Please see our video. This is the conclusion:

The 4 kW HMI is brighter than the LED lamps.
And we did not consider the fact that you can double the light output of an HMI by boosting.

But there are other topics that need to be investigated:
- What is about evenness?
- What is about energy efficiency?
- What is if you compare light output/power consumption?

I want to answer these questions in further videos.



Crash Test Lighting – what is brighter – HMI or LED?





Although testing & comparing is recommended there are some rules-of-thumb that are certainly valid in every case:

Crash test devices (distances > 4m):

In front/side crash devices 4k HMI lamps are still the best choice. Even without boost they are brighter than every LED lamp. And if it is still too little light you can boost the HMI lamp from 4 kW to 8 kW.

Sled test devices (distances 2 – 4m):

Although these LED lamps do not reach (yet) the light output of a 4 kW HMI, consider using LEDs because of these benefits:
- Better soft light.
- Less heat emittance.
- Less electric power.
Based on your HS parameters do some tests to decide: HMI or LED?

Static test devices (distances < 2m):

Devices like ‚airbag deployment‘ rigs definitely need LED lamps for these reasons:
- In these distances LED is bright enough.
- Power consumption is low.
- The light is cool.
- The light is soft.

Please keep in mind that LED lamps are good for capturing the airbag inflation. LED lamps are not good for ageing airbag units according to DIN ISO 12097-2, because their spectrum is unequal to daylight spectrum.

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