A New CODCr Online Water Quality Monitoring Instrument

The chemical oxygen demand (COD/Chemical Oxygen Demand) or the content of organic matter inthe wastewater is an important indicator of the degree of water quality pollution by reducing substances. Inorder to improve the quality of the water environment, we must have advanced COD online monitoringinstrument to monitor water pollution.This study describes a new CODCr (potassium dichromate (K2Cr2O7)as an oxidant determination of chemical oxygen demand) online water quality monitoring instrument. It isan intelligent, multi-purpose photoelectric colorimeter device. The paper makes a detailed introduction tothe various parts of the device: computer, mechanical, opto-electronics, electrical and electronic. A lot ofCOD monitor devices on the market use a metering valve for reagent metering and thus have the problemsof measurement bias.600nm single-band photoelectric colorimeter can not correct the measurement errorscaused by sample turbidity and color, can not be applied to the measurement of low concentration detection,so we need to come up with a modern water chemical oxygen demand (COD) online monitoring device. Itconducts photoelectric colorimetric detection using the dual-band of440nm and600nm, applies the newalgorithm to filter noise on the value of the photoelectric detection, uses440nm and600nm light inspectionvalue to correct through a certain algorithm for optical inspection value in the low range, and obtains amore accurate COD value. We have developed a new the CODCr line monitor using optical high and lowliquid level sensing for accurate measurement, excluding bubbling interference with the software method. Ituses a fast and accurate stepper motor power source, a more scientific control algorithm to achieve thecontrol process. The new embedded microcontrollers STM32and embedded operating system μC/OS-IIcontrol greatly reduce the cost, compared to the original PLC (Programmable Logic Controller) control.The sensor and output signal of the CODCr monitor have noise reduction circuit and use shieldingmeasures. It improves the design of the application circuit part and the reliability and stability of the device.The new CODCr online monitor resolves the problems in traditional equipment and greatly reduces the cost.