| 摘要 |
PURPOSE:To obtain the highly accurate titrating device by providing a timing circuit for preventing excessive dropping when a determination point is approached and a dropping precedence circuit for preventing hunting phenomenon at this time point. CONSTITUTION:When the titration comes close to the end, one excessive drop of reagent will exceed an equivalent point. When the titration comes close to the determination point and the duration of a saturated current exceeds a preset time, one drop of passing reagent is sensed by a sensor 7, and the timing circuit B closes a solenoid valve 5 based on the sensed signal. The current caused by the drop of reagent results in fluctuation with a very short period (hunting phenomenon) due to the effect of stirring and the like in a titration tank 1. Therefore the precedence circuit C is provided so as to open the solenoid valve 5 until the passage of one drop is confirmed by the sensor 7 in the vicinity of a circuit point. The attainment of the equivalent point is confirmed by the fact that the critical point is exceeded and this state has been maintained for a specified time. |
