Hotline：
At present, in the non-destructive testing of building steel structures, some quality supervision departments and some supervision units believe that non-destructive testing is a witness test and require the words "witness test" to be marked in all or part of the non-destructive testing report, otherwise it will not be accepted.
So, is nondestructive testing really a "witness test"?
Ministry of Construction "Jianjian [2000] No. 211 housing construction projects and municipal infrastructure projects to implement the provisions of witness sampling and inspection" the third article is so said "in these provisions, witness sampling and inspection refers to the construction unit or project supervision personnel witness, The site test personnel of the construction unit will sample the test blocks, specimens and materials involved in the structural safety of the project on the site, and send them to the quality testing units that have been approved by the construction administrative departments at or above the provincial level and the quality and technical supervision departments for measurement certification."
Why do witness sampling and inspection? For example, to reinspect the mechanical properties of a batch of steel, you have to take a number of samples from a batch of steel, and then sent to the qualified testing unit, after completing the necessary commissioning procedures, the witness sampling and sample delivery process is completed, the following test is completed by the testing unit and issue a test report. If this process is not witnessed, it is difficult to guarantee that the sample sent is from that batch of steel.
However, non-destructive testing is different, non-destructive testing is the testing unit testing personnel move the testing equipment to the scene, in accordance with the requirements of relevant standards and norms directly to the product testing, and then issue a test report, this process does not exist the sample delivery link, so there is no need to witness, the construction unit or supervision unit see whether to witness the same, The testing unit has to bear legal responsibility for the testing report issued by itself.
For the above reasons, we can conclude that nondestructive testing is not a witness test. It is of great practical significance for nondestructive testing units to clarify whether nondestructive testing is a witness test or not. Because non-destructive testing is different from other building materials tests, a small equipment can run around the country, that is, basically not subject to regional constraints, but if you think that non-destructive testing is a witness test, then because the witness test is a territorial management, it is difficult to smoothly carry out non-destructive testing business in the field; If you think that non-destructive testing is not a witness test, then you are not subject to the relevant constraints of local witness tests, so that you can carry out non-destructive testing business in different places very smoothly.
