  The wire stretching measurement was completed on the prototype Double Quarter
Wave (DQW) crab cavity for operation practice and calibration of the
measurement system. Four locations were defined to be on the electrical center
plane of the crab cavity, and survey of the wire indicated all are on the same
plane. The successful measurement validated the wire stretching system built at
Brookhaven National Lab. The offset of the four wire locations to the fitted
plane provided the error of the measurement.
