Patent ID: 9645113
Date: 2017-05-09
CPC Classifications: G01L,G01N,G08B

Claim:
1. An ionized gas detector comprising; at least a pair of ion detecting electrodes that detect ions of an ionized measuring-subject gas; an electrode-voltage applying unit that applies a given voltage to the ion detecting electrodes, the electrode-voltage applying unit being configured to be capable of reversing its voltage polarity; a charge amplifier circuit having a charge capacitor that accumulates electric charges generated by voltage application by the electrode-voltage applying unit; an ion current calculating unit that calculates a value of an ion current of ions of the measuring-subject gas, based on a time-dependent change of a volume of electric charges accumulated in the charge capacitor of the charge amplifier circuit; a concentration determining unit that determines concentration of the measuring-subject gas, based on an ion current value calculated by the ion current calculating unit; a voltage polarity control unit that reverses polarity of the electrode-voltage applying unit according to a volume of electric charges accumulated in the charge capacitor of the charge amplifier circuit; a circuit connected between the ion detecting electrodes and an input side of the charge amplifier circuit, the circuit having a voltage applying unit different in voltage polarity from the electrode-voltage applying unit configured to be capable of reversing its voltage polarity and an electric charge accumulating unit that accumulates electric charges generated by voltage application by the voltage applying unit; and a voltage polarity reversing unit that when the voltage polarity control unit reverses polarity of the electrode-voltage applying unit, reverses voltage polarity of the voltage applying unit, thereby causes the charge accumulating unit to discharge electric charges accumulated therein toward the ion detecting electrodes.