TROLL 9500 Operator's Manual - Geotech Environmental Equipment

Section 15: AmmoniumSensor Care and HandlingSensor RemovalPosition the yoke of the sensor removal tool at the pointwhere the sensor meets the sensor block and pry thesensor upward.Avoid touching the membrane at the tip of thesensor. Contaminants on the membrane canchange its properties and affect measurements.Maintenance/Inspection/CleaningsensorremovaltoolAs long as extreme pH and high organic solvent content is avoided,the sensor should last for several months at room temperature.Eventually some of the components will leach out, and this will affectthe response (detection limit and scope), but this can be compensatedthrough calibration.If film buildup is visible on the membrane, rinse under a gentle streamof clean water, or swish gently in a mild detergent solution, rinse wellwith clean water, and shake to dry.To avoid depletion of the reference solution, do not allow the sensor tosoak in pure water for more than a few minutes at a time.ReferencesEaton, A.D., L.S. Clesceri, E.W. Rice, and A.E. Greenberg, eds.,Standard Methods for the Examination of Water and Wastewater,21st edition, Washington, D.C.: American Public Health Association,American Water Works Association, and Water EnvironmentFederation, 2005. Section 4500-NH 3 Nitrogen (Ammonia). D. Ammonia-SelectiveElectrode Method.EPA, Methods for Chemical Analysis of Water and Wastes,EPA/600/4-79-020, revised March 1983. Method 350.3, Nitrogen,Ammonia, Potentiometric, Ion Selective Electrode. Approved at 40CFR Part 136.Rundle, Chris C., A Beginners Guide to Ion-Selective ElectrodeMeasurements. Nico2000 Ltd., London, UK. On the web at www.nico2000.netU.S. Geological Survey, Office of Water Quality Technical Memorandum93.12: Water Resources Division Nomenclature Conventionsfor Reporting Concentrations of Ammonium Ions and Ammonia inNatural Waters. August 26, 1993.The electrode is not customer-refillable.StorageStore the sensor immersed in 14 or 140 ppm N solution, dependingon usage requirements, rather than dry or in DI water.TROLL 9500 Operator’s Manual 1090095110 rev. 007 01/09