Dry cleaning detergent concentration sensor and dry cleaning detergent concentration control manner

摘要

PROBLEM TO BE SOLVED: To enable the measurement of concentration from both data on impedance obtained by impressing an a.c. voltage between a plurality of electrodes immersed in a cleaning liquid and data on the temperature of the cleaning liquid obtained by a temperature sensor. ;SOLUTION: In a concentration sensor 1, an electrode 3 is concentrically fixed in a cylindrical external electrode 2, and a temperature sensor 4 is protruded from the center of the internal electrode 3. A dry-cleaning cleaning liquid is contained between the electrodes 2 and 3, and capacitance occurs there. This capacitance is measured to obtain the concentration of a detergent from changes in capacitance. As the relation between capacitance and concentration differs according to temperature, the temperature sensor 4 is provided for measuring the temperature of the cleaning liquid to perform compensation by temperature. Any element whose resistance and electromotive force change by temperature may be used for the temperature sensor 4. The terminals at both ends of the sensor 4 are extracted to the outside by lead wires 18 and 19. A thermistor is a semiconductor temperature measuring element whose resistance decreases with the increase of temperature.;COPYRIGHT: (C)1998,JPO