[en] A twin matrix array transducer to make possible to detect and measure a flaw with test direction through weld of austenitic stainless steel has been developed. Each transducer performs as transmitter and receiver and has 2 lines and 16 columns array elements respectively. With this transducer depth measurement tests for cracks by stress corrosion cracking (SCC) and fatigue on austenitic stainless steel weld pipe specimens have been carried out. As the results: (1) Corner echoes and tip echoes from SCCs and fatigue cracks could be detected with test direction through the weld of the 25 mm thickness stainless steel pipe specimens. (2) The depth measurements through the weld and in base metal corresponded well. Therefore we have evaluated that the twin matrix array transducer mode possible to measure flaw depth with both the test direction and was effective ultrasonic testing technique to be able to estimate and evaluate flaw depth with more accuracy and reliability. (author)