CODA-500, Automatic COD Monitor, HORIBA

The CODA-500 is HORIBA's automatic COD monitor for continuous on-line measurement of chemical oxygen demand in industrial wastewater, based on the fully automated potassium permanganate method at 100 °C in accordance with JIS K 0806. Three model variants are available and selected at the time of order: CODA-500-A uses the acid potassium permanganate method (JIS K 0806) suitable for most industrial wastewater; CODA-500-B uses the alkaline potassium permanganate method, which is not influenced by chloride ion concentration and is recommended for high-chloride samples; CODA-500-C combines the acid method with a reagent cleaning function for operation in samples with high chloride ion concentrations (up to 100× full-scale value). Measurement is performed by potentiometric titration at constant current using a micro syringe for precise reagent delivery and direct heating at 100 °C. A key improvement over previous models is a 1/10 reduction in reagent consumption per measurement run, extending the reagent replacement interval to one month or more and significantly reducing life cycle operating costs. COD load calculation, 1-year data memory, USB data export, RS-485/Modbus communication, and an optional 2-point measurement configuration are standard or available features. The CODA-500 is footprint-compatible with the former CODA-200 series.

Key Features CODA-500

• Three model variants: CODA-500-A (acidic KMnO₄, JIS K 0806); CODA-500-B (alkaline KMnO₄, chloride-independent); CODA-500-C (acidic + reagent cleaning, up to 100× FS chloride).
• Reagent consumption reduced to 1/10 vs previous models — ≥1-month reagent replacement interval; option for reagent delivery service eliminates on-site reagent preparation.
• Wide measurement range: 0–20 mg/L to 0–2000 mg/L (9 preset ranges); optional 2-range configuration.
• Reproducibility: ±1% FS (0–20 mg/L range); ±2% FS (30–500 mg/L); ±5% FS (1000–2000 mg/L).
• Potentiometric titration at constant current with micro syringe — high-precision endpoint detection.
• Silver nitrate bypass option — eliminates AgNO₃ when chloride concentration is low, reducing reagent costs.
• COD load calculation capability using flow signal input (4–20 mA).
• Standard I/O: 3 × 4–20 mA outputs; 14 contact outputs; 1 analog input; 9 contact inputs; RS-485/Modbus.
• Color touch panel LCD; built-in thermal printer (58 mm, auto take-up); 1-year data memory; USB export.
• Optional: 2-point measurement; 2 ranges; 6 analog / 21 contact outputs; RS-232C.
• Footprint-compatible with former CODA-200 series — drop-in replacement at existing installations.

Applications

The CODA-500 is suited to continuous automatic COD monitoring at industrial wastewater discharge points subject to Total Pollutant Load Control regulations — including chemical, food and beverage, pulp and paper, textile, and other industrial facilities discharging to closed water areas — where on-line JIS-method COD measurement is required for regulatory compliance and load reporting.

Installation and Safety Notes

Install indoors on a flat, stable, vibration-free surface at 2–40 °C; avoid dust, mist, corrosive gases, direct sunlight. Power: 100–240 V AC ±10%, 50/60 Hz; 250–350 VA. Sample flow rate: 0.5–5 L/min via overflow tank (optional). Sample temperature 2–40 °C. Blank water: waterworks water (hardness ≤100 mg/L); pressure 100–500 kPa; consumption 20–420 mL per run. Use HORIBA-designated reagents only. Before operation, conduct manual JIS K 0102 analysis and enter the conversion factor. Piping length from main unit to sampling point: within 3 m.

Technical Specifications