Method and apparatus for accurately determining the presence of voltage at capacitive test points and for determining the phase angle relationship between two capacitive points. An active gear wheel and a passive gear wheel are disposed respectively on two rigid frames. The main structure has a first fixing portion and receives the flexible member. The method further includes transforming data provided by the application program from the first format supported by the first frame buffer to the second format supported by the second frame buffer for output on the output device to provide compatibility between the application program and the output device.