| 摘要 |
PURPOSE:Output voltage of a phototransistor is directly added to one input terminal of a comparator through a resistance, and to other input terminal of the comparator through a delay circuit comprising a resistance and a capacitor and error information and error control are prevented. CONSTITUTION:When the foreign type liquid different in light permeability is mixed into fluid, input voltage applied to a non-inverted input terminal N of an amplifier IC is instantaneously changed, whereas the voltage applied to the inverted input terminal I reaches at first an equal potential to the terminal N after the charge and discharge time to the capacitor C is passed. Accordingly, during this time, unbalance in input voltage between both terminals is generated, an amplifier IC outputs negative or positive signal, thereby the mixing of the foreign type material in the solution can be detected. |
