b"To protect our communities, it's critical to monitor for excessive nutrients in drinking water reservoirs.NEXT-GEN SENSING TECHNOLOGYSMALL, BUT MIGHTYNitrate can be detected by measuring theUntil recently, UV nitrate sensors were large standalone penetration of ultraviolet (UV) light through asensors that were not part of a multiparameter solution. This is accomplished using the principles ofplatform. YSIs development of the EXO NitraLEDa spectrophotometry. small, LED-based sensor that can be installed in the EXO Sondewas a real gamechanger.Those who took physics may remember that forms of electromagnetic radiation (EMR) are distinguished byTurns out, being able to simultaneously measure wavelength. Materials absorb EMR (light) differently,nitrate alongside other parameters is a big deal. with nitrate absorbing most strongly at short (250 nm) UV wavelengths. Measuring nitrate by itself can be interestingare nitrate concentrations increasing or decreasing? Sure, UV nitrate sensors measure this absorbance of light bythat's a trend you want to know, said Dr. Smith.nitrate and convert it to a concentration. But continuous monitoring on a multiparameter UV nitrate sensors are not meant to replace traditional,platform allows you to do a lot more than just look at laboratory-based nitrate analysis methods such as ion- the trend of one parameter, she explained. It allows chromatography. Still, they have become an excellentyou to really evaluate massive data sets.screening tool in the field due to their inherent advantages of being chemical-free and because theySo now its not about the trend in that parameterdont require frequent calibration, like ISEs.its about trends in the system and the relationship between variables. Thats powerful, and thats the era Most UV nitrate sensors are large, power-hungry,were entering now. and expensive, making them impractical for carrying around and for unattended deployment. That allThese environmental systems are complex, so a changed with the development of LED-basedholistic approach is needed to fully characterize how technology for monitoring nitrate. nitrate impacts aquatic health. This requires the right monitoring tools in the right places. Whos Minding the Planet? 45"