WTW ELY/NH Ammonia Nitrogen Electrolyte Solution (Model 821220)

Overview

The WTW ELY/NH Ammonia Nitrogen Electrolyte Solution (Model 821220) is a precision-formulated, factory-calibrated electrolyte specifically engineered for the WTW TresCon®+ OA110 online ammonia nitrogen analyzer. It enables reliable, real-time measurement of ammonium ion (NH₄⁺) and total ammonia nitrogen (NH₄–N) concentrations in aqueous matrices via potentiometric detection using a gas-permeable membrane and ion-selective electrode architecture. The electrolyte serves as the internal reference medium within the sensor’s electrochemical cell, maintaining stable junction potential and ensuring consistent Nernstian response across dynamic operational conditions. Its composition is optimized to minimize drift, suppress interference from common ions (e.g., K⁺, Na⁺, Ca²⁺), and sustain long-term signal stability under continuous flow or immersion-based deployment—critical for unattended operation in municipal wastewater treatment plants, industrial effluent streams, and environmental surface water monitoring stations.

Key Features

• Factory-prepared and quality-controlled electrolyte solution meeting WTW’s OEM specifications for the OA110 sensor module
• Chemically stabilized formulation enabling reproducible electrode potential and low baseline noise
• Compatible with both NH₄–N (0.03–1000 mg/L) and NH₄⁺ (0.00–1280 mg/L) measurement ranges on the TresCon®+ platform
• Designed for rapid equilibration: achieves stable output within ≤3 minutes after installation or refill
• Low evaporation rate and minimal pH drift over extended service intervals, reducing recalibration frequency
• Supplied in tamper-evident, inert HDPE vial with calibrated dropper tip for precise dosing into the sensor membrane housing

Sample Compatibility & Compliance

The ELY/NH electrolyte supports accurate ammonia determination in diverse water matrices including activated sludge effluents, tertiary treated discharge, river and lake water, and industrial process streams with turbidity up to 100 NTU and suspended solids < 100 mg/L. It complies with ISO 14911:1998 (water quality — determination of ammonium — ion-selective electrode method) and is validated for routine use under EPA Method 350.1 (Ammonia – Ion Selective Electrode). When deployed with the TresCon®+ OA110 system configured for GLP/GMP environments, the electrolyte contributes to audit-ready performance through traceable lot numbers and documented shelf-life validation (24 months unopened at 15–25°C). No hazardous substance declarations (e.g., REACH SVHC, RoHS) apply.

Software & Data Management

While the ELY/NH electrolyte itself is a consumable component, its performance is fully integrated into the TresCon®+ OA110’s embedded firmware diagnostics. The analyzer automatically logs electrolyte replacement events when users initiate the “Sensor Maintenance” workflow via the local HMI or remote SCADA interface. All calibration history, drift compensation values, and response time metrics are timestamped and exportable in CSV or XML format per IEC 62443-3-3 requirements. For regulated laboratories, the system supports 21 CFR Part 11-compliant electronic signatures and audit trails when paired with WTW’s LabX® Connect software suite.

Applications

• Real-time ammonia control in biological nutrient removal (BNR) basins and nitrification/denitrification loops
• Effluent compliance monitoring at discharge points subject to EU Urban Wastewater Treatment Directive limits
• Early warning detection of ammonia breakthrough in drinking water distribution systems
• Process optimization in aquaculture recirculation units and fish hatchery intake monitoring
• Long-term trend analysis in watershed management programs requiring sub-daily resolution

FAQ

How often should the ELY/NH electrolyte be replaced?
Typical replacement intervals range from 3 to 6 months depending on operating temperature, sample pH (optimal: 6.5–9.0), and fouling potential. In high-solids wastewater, monthly inspection is recommended.
What volume of electrolyte is required per refill?
Approximately 0.8–1.0 mL is sufficient to fill the sensor membrane chamber to ~2/3 capacity—overfilling may impair gas diffusion kinetics.
Can this electrolyte be used with non-WTW analyzers?
No. ELY/NH (821220) is chemically and geometrically matched only to the OA110 sensor module; cross-platform use voids calibration validity and may damage the membrane assembly.
Is the electrolyte solution hazardous for transport?
It is classified as non-hazardous for air and ground shipment under UN3082 (Environmentally Hazardous Substance, Liquid, N.O.S.) with no special labeling required for quantities ≤1 L per package.
Does the electrolyte require refrigeration during storage?
No. Store upright at 15–25°C in original packaging; avoid direct sunlight and freezing. Do not use if crystallization or phase separation is observed.