A bi-fold knife locking mechanism is provided which maintains the open and closed positions associated with the bi-fold knife. A process for reading out to the main memory an amount of change in failure in accordance with particle numbers calculated for individual defect sizes from second inspection data representative of a result of equipment QC is applied to the production unit. The second transistor, the third transistor, the fourth transistor, and the fifth transistor are corporately used to output a compensation pulse; and the sixth transistor is used to output the compensation pulse to a gate terminal of the first transistor thereby compensating a control signal. The addition of substances, such as soluble metals, that attract oxygen may form a protective oxide layer over the remaining portion of the rhenium-alloy part or piece.