... 4)High efficiency 5)Good price Multi-channel eddy current metal detector & Digital tube tester The specialties of instrument Numerical control operation ... the glabrous metal surface) Gain0~90 dB,0.5 dB adjustable Digital array 0~359 degree,1 degree adjustable Fast electronic imbalance ... , multi-windows, multi-time base displays. Multi-channel eddy current metal detector, digital tube tester