can greatly influence the test results. Also, there has to be strict control of the test environment. A deviation in the medium's temperature can cause the creep rupture time to vary drastically. In some cases, a temperature change of 1 degree Celsius affected the creep rupture time by 13%. Lastly, this test is again a destructive test, so the host part will be destroyed by conducting this type of test. Non-destructive testing Visual examination Visual inspection, just like the name implies, is a visual investigation of the weldment. The inspector is typically looking for visual indications such as discolorations, weld defects, discontinuities, porosity, notches, scratches, etc. Typically visual inspection is broken down into different categories or groups for the qualifying inspection criteria. These groupings may vary among standards and each group has a certain level of imperfections that they consider acceptable. There are 5 tables and a chart found in DVS Standard DVS2202-1 that show different types of defects found by visual examination and their permissible acceptance criteria. Visual inspection is very advantageous in the fact that it is quick, easy, inexpensive, and requires very simple tools and gauges in order to conduct. Because it is so quick, it is typically required to have a weld pass visual inspection prior to being able to have any additional nondestructive test conducted to the specimen. In contrast, the inspection needs to be completed by someone who has a lot of experience and skill. Additionally, this type of test will not give any data into the quality of the weld seam. Because of the low cost, if a part is suspected to have issues, follow on testing can be conducted without much initial investment. X-ray testing X-ray testing of plastics is similar to that of metal weldments, but uses much lower radiation intensity due to the plastics having a lower density than metals. The x-ray testing is used to find imperfections that are below the surface. These imperfections include porosity, solid inclusions, voids, crazes, etc. The x-ray transmits radiation through the tested object onto a film or camera. This film or camera will produce an image. The varying densities of the object will show up as different shades in the image thus showing where the defects are located. One of the advantages of X-ray is that it provides a way to quickly show the flaws both on the surface and inside the weld