We have extended the experimental approach, used by Yu. A. Nastyshyn et al. [J. Appl. Phys. 86 , 4199 (1999)] for measuring polar anchoring strength, to measure the twist elastic constant in nematic liquid crystal. The method implies measurements of phase retardation changes in liquid crystal under the action of magnetic field. The obtained experimental data were fitted with the predictions of elastic theory. We found that the value of the measured elastic constant, K-22 , is in good agreement with those described in literature.