Measure the thickness of the Al inside the straw

This measurement still has to be done: we will weigh the straw and calculate the thickness of the Aluminum layer.

The weight of a 2m straw is 15.55 +- 0.05 g - the thickness of the Kapton is 10 um as specified by the supplier. The problem is there is also some film over it and we do not know the thickness of that. The only thing we can do is calculate the maximum thickness of the Al layer. This is calculated to be lower than 4.7 +- 0.2 um. The supplier specs < 5 um.