Research On The Remote Monitoring System Of COD Detection Based On GPRS

With the serious water pollution situation and the improving of human consciousness of environmental protection, a rapid and accurate detection of water quality has become one common focus. The COD measurement method is accordingly developed from manual detection to the stage of remote automatic monitoring. In view of the problems of most COD automatic detection devices in the field of environmental monitoring, such as the sampling measurement method is inflexible and its accumulated error is bigger, the inaccuracy detection of mild pollution water and low real-time reporting of water quality information. Considering the above, this paper aims to study a kind of remote monitoring system applicable to water COD detection.Based on the automatic detection technology of COD value and GPRS technology, this study designed a GPRS-based remote monitoring system of COD value. To solve the problems mentioned above, the following several aspects are mainly involved:(1)Analysis of continuous sampling measurement method and related device design. In view of the sampling measurement problems of most COD automatic detection devices at the present time, a continuous sampling measurement method is proposed, based on which the device can realize flexibility and relatively high precision of the sampling measurement.(2)The device of dual-wavelength detection design and related model establish. Part of the standard water samples whose COD concentration is known are chosen as the experimental sample. After digestion reaction and dual-wavelength photoelectric detection, the COD prediction model is established based on BP neural network, which can be used to realize the accurate prediction of the water COD value.(3)Analysis the reliability of the GPRS wireless data transmission. The error control technology, custom packet format, heartbeat packets mechanism and other measures are used to reduce error rate of data transmission, thus improves the reliability of remote data transmission.(4)The COD remote monitoring experiment platform is established and tested. COD value remote monitoring system based on GPRS is developed and related hardware and software are designed. The design of hardware part mainly includes the minimum system, dual-wavelength photoelectric detection module, continuous sampling measurement module and GPRS communication circuit. And the design of software part mainly includes remote monitoring terminal software, etc. After a test is completed on the experimental platform, then analysis the stability and practicability of the system.The experimental results show that the continuous sampling measurement method is flexible and reliable, its sampling measurement accuracy can meet the requirement of COD automatic detection device. Photoelectric detection system with dual-wavelength has high precision and sensitivity in detecting low concentration COD water. Using custom data packets, error control and mechanism of heartbeat packets can guarantee the stability of GPRS data transmission and achieves the ideal effect.