Test technics provides motor-driven semi-automatic twist testers for accurate counting of twist per meter [tpm] of twisted yarn. These ergonomically designed instruments count the twists of the yarn by untwisting it completely and displaying the reading on 4-digit led display directly in terms of tpm. The instruments use adjustable speed motor and operate on 250 mm test length, thus offering convenience of operation compared to existing models. They are highly useful in textile industry for checking the quality of twisted yarns. The twist testers are useful for multi- filament or 2/3 ply yarns for measuring twist by pin separation method. The instruments have facility to select s or z direction of twists, reversing the direction of motor and up/dn count facility on digital display for over run test in semi-automatic mode. They are also provided with measuring and elongation scale to ensure 250 mm test length and to measure the elongation at fully untwist position. The twin testers are supplied with set of weights to put the yarn under test in tension.