  A twisted multifilamentary structure is needed for Nb3Sn and NbTi strands to
be used in the International Thermonuclear Experimental Reactor (ITER) magnets.
As important parameters for the superconducting strands design and production,
the twist pitch length and direction of strands must meet the requirements
according to ITER Procurement Arrangement (PA) and this must be verified. The
technical requirements are 15mm+/-2mm for twist pitch length and right hand
twist for direction. The strand twist pitch and the twist direction can be
measured on straight sections of strand, which is recognized by the repetition
of filament bundles or by the angle of the filaments. Several test methods and
results are described and compared in this paper. The accuracy, uncertainty and
feasibility of different methods are analyzed and recommended measurement
methods are proposed for ITER strands verification.
