1, on the resolution of the problem, in fact, regardless of how the manufacturer said, in fact, now domestic production of the test machine are absolutely able to meet the requirements of the test machine, too high a resolution of just chewing with the sales promotion, there is no practical significance. Have to say that you mention the two resolution which is good, can only say that the maximum test force of 1/5000 better;

2, the second and third questions are related, generally with DC servo motors, the test machine beam moving speed is 1 - 300mm/min; with AC servo motors, the speed of the test machine can be up to 0.05 - 500mm/min; so of course, the latter is better, and AC servo motors, the test machine speed can reach 0.05 - 500mm/min; so of course! The latter is better, and AC servo motors are generally imported motors, its speed accuracy is higher; but the latter test machine price is also higher;

3, according to your first three questions, you choose the test machine should be an electronic tensile tester or an electronic universal testing machine, so there is no chain drive, it should be synchronous belt drive. Synchronous belt drive is more stable, synchronization is also better, faster and less noise.

Ha ha, as for your choice of which test machine, I can not say anything.