Abstract: A test manipulator comprises a floor stand with a vertical column to support the weight of a test head. The vertical column includes a shaft along which a cradle assembly for the test head can be slid up and down, pivoted, and twisted. A tool balancer is connected to the cradle assembly and provides for weightlessness by counterbalancing. A fall arrester is independently connected to the cradle assembly to allow slow unimpeded movements of the cradle assembly up-and-down, and to automatically lock-up to prevent a sudden fall of the cradle assembly. Releasing the load prevented from falling will reset the fall arrestor.