The New Crown kit mainly refers to the COVID-19 Antigen Rapid Test Kit (Saliva), where only a bar appears in the C zone to indicate normal. Usually there will be two areas on the test paper that show red bar, one of which is C, indicating the quality control area, and the other is T, indicating the test area, which generally requires both C and T areas to show a red bar to indicate a positive result, which is not normal. 1. Normal situation: COVID-19 antigen rapid test kit can determine whether there is a new coronavirus infection in the body by detecting saliva, after waiting for 15 minutes The presence of the C zone is mainly to show that the test result is valid, so on the basis of the valid result, there is no bar in the T zone, indicating that there is no virus infection in the body or the number of viruses present in the body is low and cannot be detected, which can basically be judged as negative; 2, abnormal situation: If the test result shows two bars, it is positive The results, then the possibility of new coronavirus infection in the body is greater, should be reported to the community in a timely manner, after good isolation and protective measures, to the designated medical institutions for nucleic acid testing, in order to clarify the diagnosis. However, due to the large quantity of kits produced, a small number of kits may be of substandard quality, which may lead to deviations in the results. Therefore, the significance of whether or not a bar appears in the C zone is equally important. If no bar appears in the C zone, but only in the T zone, or if no bar appears in the C and T zones after waiting for 15-20 minutes, it means that this test is invalid and it is recommended to replace the kit and retest.