Operator performance in a blind test piece trial

The task of an operator engaged in nondestructive testing (NDT) is to make a decision concerning the integrity of a component based on diagnostic information. The present study looks at operator performance in a blind test piece trial. The main aim is to improve performance by exploring the underlying factors of operators' successful decisions. A second aim is to find out how to make qualification tests more valid. Sixteen operators performed ultrasonic inspections of four test pieces with the aim to find implanted cracks. In addition to these performance demonstration tests (PDT), the operators performed independent ability tests and filled out questionnaires. There was a great variance of inspection performance. The ability tests were not successful predictors of operator PDT performance. The results also show that operators who have a positive attitude towards the procedure crud yet trust their instinctive feeling more than the procedure in difficult situations have a higher PDT performance. These results emphasize the need for operators to be motivated when performing NDT.