Aiming at difficult key problems of high corrosive

lots of impurities and difficulties for long-term monitoring in the field of dissolved oxygen concentration monitoring in mining production

a kind of in-situ dissolved oxygen detecting and system

which has high-precision

high anti-interference and quick response is designed. The system has mechanical protection structure of anti-corrosion and wear

and precise photoelectric detection AC amplifier and digital phase-detecting circuit is designed based on fluorescence quenching principle

phase deviation detection scheme is achieved by multiple order integral average filtering technology. Through field contrast experiments show that the system has high-precision

quick response（ not more than 30s） and strong antiinterference capability

it can still work stably in harsh environment for a long-time

which can accomplish mission of dissolved oxygen concentration in-situ on-line monitoring in mining industry field.