Best method to verify fiber type

I am going to be purchasing a custom fabric made with S2-glass roving…or at least that is what I spec-ed. Because I do not know who the weaver is, I would like to verify that what I received is not E-glass. What is my best method? Can I reasonably expect a dry roving to hit the datasheet value of 4600 MPa in a tensile test? Or is this single filament value far too optimal for a roving that has been processed? Is it better to test impregnated for the impregnated strand tensile strength?

I would recommend doing an impregnated strand tensile test (ASTM D2343) and measure both strength and modulus if possible. Note that this test will show less than the “pristine” fiber strength, and S2-glass should show strengths in the 3400-3800 MPa range, while standard E-glass will be around 2000-2500 MPa. Tensile modulus would also be about 15-17% higher for the S2-glass

tgundberg, thanks for the advice. Looks like I will be doing either a D2343 or D3039 for verification. The D2343 will probably be a closer match due to a more controlled Vf.