Balancing sensitivity and accuracy of presentation is varied. Commonly referred to Instrumentation accuracy, amplitude error, indicates, or full scale expressed as a percentage of the value, and phase error. For dynamic balancing machine, but, according to correct imbalances with such precision that indicates, and use the amount of allowable residual imbalance of the rotor up to a certain limit, the initial unbalance of rotor, this error is too stringent for small initial unbalance of rotor, and this error seems very loose. In addition, even if there is a certain amount of amplitude and phase errors within certain limit residual unbalance will gradually decrease, but reaches a certain limit can no longer be small. The other hand, sensitivity refers to the so-called indicates adding a scale indicating instrument must be inequalities imposed by measure, these values increase with the quality varies.