A voltage detection section and current detection section detect a voltage and current supplied to a motor, and the detected voltage and current are supplied to a position detection section. The modules may be connected in order to provide an optimal solution in a food freezing or chilling process. The second spring is different from the first spring and disposed together with the first spring on one side of a carrier to support the carrier. An elongated nib is mounted in the supply passage and has an end extending from the passage, the nib engaging the member so that the member moves to its open position. The method may be performed by a network testing system. A method for preparing the chemical mechanical polishing slurry and a chemical mechanical polishing method using the chemical mechanical polishing slurry are also disclosed.