YSI Digital VARiON® Ammonium/Nitrate/Potassium/ Chloride for the IQ SensorNet System The VARiON is a rugged, online probe for measuring Nitrate and Ammonium concentrations with Ion Selective Electrodes (ISEs) in wastewater process applications. The VARiON probe is used within the IQ SensorNet system and can therefore be networked with other probes and parameters for a complete process monitoring and control system. It can measure, report and control off of the ammonium and/or nitrate measurements with automatic compensation for potassium (for ammonium) or chloride (for nitrate). Parameters: Nitrate Ammonium The VARiON is the ideal probe for quantitative measurement of nitrogen in a wastewater treatment plant. The efficient control of Nitrogen in wastewater relies on the ability to take the measurements directly in the process. This direct ISE measuring technology is possible with the VARiON sensor, enabling optimization of a plant in respect to process efficiency and energy consumption. Potassium (compensation & can be reported) Chloride (compensation only) Single- or dual- measurement of ammonium and nitrate; measurement of potassium or chloride for automatic compensation Individually, user-replaceable electrodes and reference • The VARiON probe provides continuous ISE data to help control & optimize the wastewater process. VARiON reference system is very stable over long periods of time Electrodes are recognized automatically Factory calibrated with optional in-situ calibration for improved accuracy • 2-year warranty on the probe, 1-year on electrodes

VARiON Plus 700 IQ Technical Specifications Parameter NO3 NO3-N mV (Nitrate) NH4 NH4-N mV (Ammonium) K mV (Potassium) Cl (compensation only) mV (Chloride) Temperature Measuring Range Resolution .5 to 450.0 mg/L 0.5 mg/L 5 to 4500 mg/L 5 mg/L 0.1 to 100.0 mg/L 0.1 mg/L 1 to 1000 mg/L 1 mg/L -2000 to 2000 mV 1 mV 0.1 to 129.0 mg/L 0.1 mg/L 1 to 1290 mg/L 1 mg/L 0.1 to 100.0 mg/L 0.1 mg/L 1 to 1000 mg/L 1 mg/L -2000 to 2000 mV 1 mV 1 to 1000 mg/L 1 mg/L -2000 to +2000 mV 1 mV 1 to 1000 mg/L 1 mg/L -2000 to 2000 mV 1 mV -5 to 60 °C (23 to 140 °F) 0.1 ºC Accuracy=+ 0.5 ºC Operating & Compensation...