On the measurement of the Casimir torque

We discuss the possibility of measuring the recently proposed Casimir torque between bi-refringent crystals, using a torsion pendulum in dark vacuum. By simulation, we analyze the effects of precession, surface polish, and torque due to stray charge. We determine the experimental conditions under which the torque might be measured, and conclude that these are achievable with modern instrumentation, and we give an estimate of errors.