T.O. 33B-1-1 4-45 Table 4-5.  Eddy Current Instruments – Applications, Features and Limitations. General Features Instrument Application Type Frequency Output Limitations Hocking UH-B Locator Cracks and flaws in magnetic and nonmagnetic material; general purpose sorting. Impedance (Amplitude only) 200 kHz 2 MHz 6 MHz Meter Single coil testing; no phase analysis; no low frequency capability. Staveley NDT-19e Flaw detection; conductivity and thickness measurement; multi-layer inspections; dual frequency mixing Impedance Amplitude & Phase Freq 1 = 50 Hz - 2 MHz; Freq 2 = 100 Hz - 1 MHz; Dual Freq: variable Impedance plane display; recorder; external printer Staveley NDT-19eII NDT-19e plus semiautomatic bolthole scanner Zetec MIZ-20A Flaw detection, conductivity; thickness measurement; multi- layer inspections Impedance Amplitude & Phase 50 Hz - 2 MHz, variable Impedance plane display; recorder; external printer No signal mixing ( single frequency); no digital conductivity display Physical Acoustics PD-214 Flaw detection, conductivity, thickness measurement, bolt hole scanner, probe characterization, C-scan, waterfall presentation Impedance Amplitude & Phase 50 - 3 MHZ Impedance display RS232 output Floppy disk external printer Zetec MIZ-22 Flaw detection, conductivity; thickness measurement; multi- layer inspections Impedance Amplitude & Phase Freq 1 = 100 Hz - 2 MHz; Freq 2 = 100 Hz - 1 MHz; Dual Freq: variable Impedance plane display; recorder; external printer