What is the conversation mainly about?

W: Dr. Smith? This is Jennifer Williamson from the Daily News. [7] I’d like to ask you some questions about the new official standard weight that you purchased.
M: I’d be happy to help you.
W: First of all, how is the standard weight used?
M: Well, [8] we use it to check the scales all over the country. Our department of weights and measures is a government agency. It’s our responsibility to see that all the scales measure a kilogram accurately. So this is the way we use to adjust the scales.
W: How did you check the scales before?
M: We have an old standard weight. [9] It had to be replaced because it was imprecise. You see it was made of poor quality metal that was too porous. It absorbed too much moisture.
W: Oh. So when the weather was humid it weighed more and when it was dry it weighed less.
M: Exactly. And that variation can affect the standards of the whole country. So our department had the new weight made out of higher quality metal.
W: How much did it cost?
M: About 45 thousand dollars.
W: 45,000 dollars? For one kilogram weight? That’s more expensive than gold. [10] Is it really worth that much?
M: [10] I’m sure it is. Industries depend on our government agency to monitor the accuracy of scales. So that when they buy and sell their products there is one standard. Think of the drug industry, for example, those companies rely on high accuracy scales to manufacture and package medicine.