| 摘要 |
PURPOSE:To make it possible to easily carry out an emission spectroanalysis employing an inductive coupling plasma light source device (ICP), by automating the operation for effecting impedance matching between a power source and a load in the ICP. CONSTITUTION:The output of a high-frequency power source 1 is sent to a matching box 3 through a coaxial cable. On the way, the progressive wave from the power source 1 to the box 3 is passed through a phase detecting ciruit 2 to detect a phase difference between voltage and current thereof. The matching box 3 is constituted by capacitors C1 and C2. The capacitor C1 is adapted to be driven by a motor M. A phase signal processing circuit 5 adds to the output of the circuit 2 a proper bias set by a sequence controller 6. The output of the circuit 5 is applied, as a control input signal, to a motor driving controlling circuit 4, which drives the motor M until the signal becomes 0. Thus, it is possible to realize an optimum matching state under all circumstances simply by regulating the capacitor C1. |
