What equipment do I require to measure the polarization characterisctics of sheet linear polarisers and retarders? Most of the equipment I find is for electro optic applications for communications etc.
A good start is a Minolta Luminance meter like the LS-100 for stable measurements and then a "standard" linear polarizer like a 3M/Polaroid HN42HE with known properties. You can then rotate this over your test polarizer over a stable light table or aim through it at the sky to measure max and min extinction ratios and calculate SNR etc.