1.   But Barrett said more advanced tests such as X-rays, ultrasounds and infrared imaging are required.

2.   Using a variety of techniques, from X-rays to infrared imaging, modern conservators can find out.

3.   Called infrared thermal imaging, the technology is already used for limited medical testing in people and livestock.

4.   Its products include infrared imaging and electronic jamming equipment, aircraft engine controls, and electronics for satellites and missiles.