A turbine airfoil system for forming a turbine airfoil that is usable in a turbine engine. In one embodiment the method for calibrating a microphone comprises operating a MEMS device based on a first AC bias voltage, measuring a pull-in voltage, calculating a second AC bias voltage or a DC bias voltage, and operating the MEMS device based the second AC bias voltage or the DC bias voltage. 12 mum is not more than 15 countscm2 after repeating the SC-1. One of the front or rear plate includes a protruding member and the other of the front or rear plate contains a groove wherein the protruding member of one storage shelf can be engaged in the groove of another storage shelf, allowing multiple storage shelves to interconnect. The ions are coupled from the first analyser region to the second analyzer region. However, the athlete may desire to run one part of the laps fast and the another part slower by setting one predetermined delay longer than the other predetermined delay.