FTA Direct Current Potential Difference (DCPD) System
The FTA Reversing DC Potential Difference System includes the SV-5V20 FTA Constant Current DC Power Supply and the DV-EN2 | DV-40K DCPD Amplifier System. The new system offers a number of improvements over the legacy FTA DCPD systems, including improved typical crack length precision on the order of 0.0002 inches or better for typical fracture mechanics specimens and conditions. This system has been completely redesigned to provide the precise current and amplifier stability necessary for the reversing DC potential difference method of monitoring crack length.
The SV-5V20 power supply has a current and voltage rating of 20 amps and 5 volts, respectively. Solid-state polarity-reversing relays have been internally integrated and are controlled by two digital logic signals that allows for either pulsed or manual operation. This system provides ~30% better long-term stability on output current when compared to the legacy Ametek PD5-20 power supplies.
The FTA DV-EN2 | DV-40K true differential amplifier system provides (2) DV-40K amplifier channels as standard for active and reference probes. The PD input signals are amplified using precision differential amplifiers to provide a maximum gain of 40,000x, with gain selections of 500x, 1,000x, 2,000x, 5,000x, 10,000x, 20,000x, and 40,000x. These high gains and wide gain selections offer a significant advantage over the legacy Ectron 428-O amplifiers, and the output noise is also a factor of 10x less. Unique features also include auto-zero of the input signal and integrated PD output low-pass filters.