, reflections, dispersion)  and then, by the recording system.
Among 3D measurement methods (Chen et al., 2000) based on phase displacement extraction, Fourier Transform Profilometry (FTP) (Chen et al., 2005) has the characteristics of high accuracy and fast processing speed, and only a single frame of image needed to achieve 3D reconstruction.
Since the phase displacement is truncated to [-[pi], [pi]), as shown in Figure 4.
These values were calculated from the nominal resistances and the maximum 1.25 degree typical phase displacement
at 100 kHz.
The current error and the phase displacement of current transformers indicate the accuracy class of a designed current transformer .
The used field-circuit method has given the possibility to accurately determine the current error and the phase displacement of current transformers as well as equivalent magnetic characteristics of cores made of different materials.
However, phase displacement technology can be used to accurately measure torque directly at the coupling to within 1% of full-scale torque, a combination of all electrical and mechanical sources of error.
Because of the intermeshed pickup teeth, the system is referred to as a single channel phase displacement system, producing two independent torque measurements (Figure 1).
Gorman and Shrestha (2002) tested two log shear walls using the sequential phase displacement
Allen made a distinction between a strain gauge system, which measures strain through the change in resistance of a metal foil or wire that is bonded to a stressed element, and a phase displacement
system, which measures the windup of a rotating shaft.
As the shaft rotates, two sinusoidal signals are generated and carried by cable to the Torquetronic Readout Unit, which measures their phase displacement
By using the proposed solutions we obtain a higher precision of the measurements, limiting the risk of errors, which can occur in case of small phase displacements
. Obviously, the risk of error increases when the two curves of checked voltage have different variation laws.