AUTOMATIC ACID VALUE MEASURING APPARATUS

摘要

PURPOSE:To electrically and automatically measure the acid value of a substance being measured, by grasping said acid value as an optical change by titration. CONSTITUTION:The voltage e1 at the starting of injection is stored in a store element SH1. The light from a light source LS is applied to the solution of a substance to be measured. The output is received by means of a phototransistor PT, and the resulting change in color is drawn out, amplified an amplifier AF and passed through a comparator CP to obtain a signal of the termination of titration. Thereby, the voltage e2 at the termination of titration is stored in a store element SH2. The starting voltage e1 and the termination voltage e2 are led to a subtracting operational amplifier SB to obtain a voltage e3 proportional to the titration amount. Then, the difference between said voltages is attenuated in an attenuator AT, and correction for the nonvolatile portion is made to obtain a voltage e4. On the other hand, the quantity of the substance being measured is stored in a store element SH3 as a voltage e5. At the termination of titration, the voltages e4 and e5 are led into a dividing circuit DV, and the result is converted into a frequency, which is read by means of a counter DC. Thereby, the acid value is directly read.