Aqua Watch: A Nitrate Sensor with Color Intelligence

Monitoring nitrate levels in water bodies is crucial, as excessive nitrate concentrations can cause eutrophication and potentially harmful impacts on human. This paper presents the realization process of a nitrate sensor with color intelligence to detect the nitrate-concentration dependent shift in intensities of yellow color when aqueous nitrate reacts chemically with acidic brucine sulphate solution. An UV-VIS spectrophotometer was used to calibrate the sensor. A machine learning mathematical was developed. A few of the performance indices such as accuracy (± 98.78 %), sensitivity (~2.5 mV /ppm), stability and ease of use were investigated. The operating range of the sensor was 1–100 ppm (extendable range) with Least Detection Limit (LDL) as 1 ppm. The output from the sensor is fed to the ESP 8266, which has built-in Wi-Fi connectivity and embedded TCP/IP networking software, to process the machine learning mathematical model and communicate the data to the internet for in situ and remote measurements and future uses.