Q: Where do you test your products and components? A: All our products are tested inside the core of General Atomics TRIGA Mk II nuclear research reactor in Jožef Stefan Institute, Reactor Infrastructure Centre in Ljubljana, Slovenia, EU. This includes all mechanical parts (housing, screws, optics, diffuser, gaskets, coatings, connectors, wires etc.) and all electronic parts including LEDs and complete LED control gear (driver). Q: Which part of your Luminaire is tested to radiation? A: Each and every part of our product is tested with gamma and neutrons. #DITTO CHRISTMAS LIGHTS FULL#All our products have full nuclear qualification and tests, performed by third party certified laboratories. The material of the housing however does not have any impact on LOCA compatibility.įAQ: Radiation related questions Q: Do you test your products with radiation source, or you just compile public documents describing radiation hardness of electronics/materials? A: We always test our products and never assume anything. Due to very poor thermal performance of the Stainless Steel, the maximum allowed ambient operating temperature is limited to 50 o C (Aluminium version 80 o C). How do you solve this problem? A: For applications inside the RB we are offering Stainless Steel version of the Luminaires. Q: Aluminium is not allowed in areas where hydrogen generation might be the problem. exchange of the heat with the surrounding media. In both cases the same material regarding thermal conductivity, but anodized one has 20 times better emissivity, i.e. An aluminium foil (glossy finish) has emissivity coefficient of 0.04, while anodized aluminium has the emissivity of 0.8. Any glossy finish of the heat sink material has bad emissivity and therefore slow exchange of the heat energy with the surrounding air. It shows the ability of the material to exchange heat energy with the surrounding media. Q: What is emissivity of the material? A: Emissivity is the surface property of the material. The only effect is heavy, bulky product, without proper cooling. You can add stainless steel cooling fins to infinity without results. Q: You can compensate bad thermal performance of the stainless steel by adding more cooling fins, right? A: Wrong. Stainless steel has by far the worst thermal performance. We tested the same Luminaire housing made out of copper, aluminium and stainless steel. Q: Did you try to make the same Luminaire in stainless steel/aluminium/copper housing? A: Yes, we tried. This is the obvious reason, why we promote aluminium for LED Luminaires. In fact, the ability of stainless steel to conduct heat is one of the worst in metals. Here are some thermal conductivities in W/mK: Air: 0.02 Wood: 0.04 Concrete: 0.8 Stainless steel: 16 Iron: 80 Aluminium: 200 Copper: 400 Diamond: 1000 From the table above it can be seen, that the stainless steel has poor ability to conduct heat. Q: What is thermal conductivity? A: Thermal conductivity is the ability of the material to conduct heat. Keeping operational temperature as low as possible has always been our main design goal. Heat is number one killer (beside the radiation, of course) of any electronics and drastically reduces the lifetime of the product. Why do you promote aluminium housing? A: Because stainless steel has extremely poor thermal conductivity. Scientific and medical nuclear facilities with highest gamma and neutron requirements.Most demanding Hot cell applications with highest radiation tolerance required.Containment and spent fuel storage areas where LOCA and seismic certification according to the post-Fukushima requirements are a must.NPP areas with the highest radiation impact.Whole family has LED driver/electronics installed inside the Luminaire. No external boxes mounted elsewhere outside the radiation zone. World’s first and only “all in one” nuclear grade LED solution.World’s first and only LOCA tested and certified LED Lighting products.World’s highest tested and certified radiation tolerance in LED lighting industry: TID > 500 KGy.
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