Hi to all. I am a new member and I hope i've posted this thread in the right section. Well, I'm an Electrical Engineering Student. I've got a problem. We've been asked to answer a question about photometers or luxmeters used in the Ulbricht Integrating Sphere. The main question is why does the luxmeter's sensor play such a big part on the luxmeter itself, and we've been asked to find different types of materials used for luxmeters sensors. I'd really appreciate any help you can give! Thanks!