Abstract: The present invention is an improvement for use in combination with an apparatus for determining stress and percent retained austenite in a specimen so the apparatus may be used to analyze both Nickel and Titanium alloyed materials. The apparatus includes a first X-ray source with either a copper or cobalt target which irradiates with an X-ray beam a surface area of the specimen impinging on the surface area at a particular angle and a second X-ray source with either a copper or cobalt target which irradiates with an X-ray beam the same surface area of the specimen simultaneously impinging at another particular angle. The apparatus also includes a first detector tube and a second detector tube, each of which has a combination filter of iron oxide and steel foil, for detecting diffracted X-rays in particular crystallographic planes.