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We’re at one of the UK’s leading firework manufacturers
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and this is their 125 mm air starburst shell.
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A 20-minute display will not drop 10,000 fireworks.
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And 60% of them will release bad boys.
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Each one costs around £ 30 and contains half a kilo of explosive.
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And we have to launch it to a height to over 100 meters.
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As you can see, it’s much more than a bowl of loose powder.
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And this is how they test the component parts.
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The basic firework recipe is flash powder,
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a potent form of gunpowder.
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It’s a mixture of Potassium Perchlorate and Aluminium.
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These ingredients are mixed together in 7 kilo batches
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and a small sample is ignited to make sure it has a requisite brightness.
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This sample has been mixed with Strontium to make it glow red and it’s clearly a pass.
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Well, this sample has Barium added to glow green.
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Again, it does the trick nicely.
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If a firework is packed with this loose powder,
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it would explode in one instant flash.
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So the gun powder mixture is turned into pellet to prolong the burn time.
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As the burning pellets go to the sky,
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they create the spreading patterns we are all familiar with.
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This test checks whether this particular pellets size will burn of its efficient time
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to create a burst diameter of 18 meters.
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There are two roughly formed rings of stars – central ring and an outer ring.
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The outer ring is made of stars of a slightly larger size.
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Therefore their behaviour and when they burst in the middle
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ignites these stars and blows them in the circle formation.
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The initial will be the heavy larger stars will travel further.
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That’s in the sky you’ll see one small ring and then a larger ring around it.
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The next test checks the fireworks 2 fuses.
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Firstly, a length of fuse is measured down to which it’ll slowly burn inside the firework
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to ensure it ignites at the correct altitude.
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A fuse this length should burn any about 12 seconds.
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It has, so it’s a pass.
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As second external fuse is needed to lose the firework.
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Racking the fuse in paper should contain the hot gases
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and make the fuse burn much quicker.
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We expect this link to fuse to burn within a hundred fifty second.
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Looks like a pass to me.
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The final test is to ensure the firework is no louder than European regulation of 120 decibels.
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The same noise level as enigmatic drill at close range.