HYDROGEN ION DENSITY SENSOR

摘要

Ion-sensing field effect transistor(10) generates electricity according to hydrogen-ion in solution. Amplifier(OP1) amplifies this transistor(10)'s output. The reference field effect transistor(20) puts hydrated gel not sensitive to hydrogen-ion of solution on the sensing film of ion-sensing field effect transistor, and forms the liquid-surface on a part of it. Amplifier(OP2) amplifies this transistor(20)'s output. Amplifier(OP3) causes differential amplification on amplifiers(OP1, OP2) automatically.