The YSI IQ SensorNet NOx sensor uses a reagentless, UV-based absorption measurement that is built into a rugged, corrosion-resistant field probe for the IQ SensorNet system. The NOx sensor measures the sum of nitrate (NO3-N) and nitrite (NO2-N) to determine NOx-N (NO2+3-N). Measurements can be displayed as NO3-N or NO3. The NOx sensor measures nitrogen at a wavelength below 250 nm. A second wavelength is also measured in order to compensate for turbidity and organic matter that is in the water. The NOx sensor provides continuous data to help operational improvement decisions. The probe’s builtin UltraClean® ultrasonic cleaning technology reduces routine maintenance requirements.