FORT MYERS, Fla -- One month after we put copper in test jars with drywall, we test the materials to see how much they changed.

In just a week, we started seeing change in the jar with chinese drywall.

After four weeks, it was noticeably tarnished.

To see exactly how much those pieces of wire changed, Engineer Zed Hejzlar brought a machine to x-ray the copper and read the chemicals in it.

The copper in the jar with no drywall--our control jar--contained no sulfur.

The copper in the jar with drywall we got from a hardware store also contained no sulfur.

The copper in the jar with drywall from Julie's home also contained no sulfur. Our engineer tested two samples from that copper piece. Both contained no sulfur.

Finally, he tested the piece of copper inside the jar with chinese drywall.

The wire was visibly discolored, and right away the machine registered sulfur. The final result was the sample contained 2 percent sulfur.

"That's a significant amount," said Hejzlar.

"We got a lot of emails saying why didn't you put water in here?" asked Call for Action reporter Melissa Yeager.

"The reason you do it this way is because you haven't influenced the test in any way shape or form and still you get the reaction," said Hejzlar.

While our test shows the sample from Julie's home had no sulfur, it still doesn't answer julies question.

Experts say all our test does is rule out that single piece didn't have any contamination. It doesn't say anything about the rest of the drywall in Julie's home.

Experts also say it can be difficult to determine American drywall that has problems like the drywall from china--because there are "hot spots" or pieces and sections around homes with problems while other parts can be just fine.

To test your drywall at home you can place a small piece of copper wire directly into your drywall to see how much it tarnishes.