... 128 or more channels 3. ultrasonic testing UT 1 Digital Multi-channel Ultrasonic flaw detector machine for big size tube ... 2,4,8,16 Operation mode Single probe transmitter and receiver, dual probe transmitter and receiverScan mode A,B,C type ... -1024 (Optional)Detector modepositive, negative, bi-directional, radio frequency (RF)Peak memoryCan choose echo peak memory display,background peak ...