1) Better than 1% accuracy 2) 0.2% of repeatability 3) 4¡Á16 English letters LCD display 4) Operate with clamp on transducers 5) RS 232 interface or 1-channel isolated OCT output 6) Pipe diameters from 15mm to 6000mm 7) Ni-MH battery operation of over 12 h 8) 90~230VAC power supply 9) Internal data logger Bilingual interface in Chinese and English