VELP ECO Series COD Digestion Block
| Brand | VELP |
|---|---|
| Origin | Italy |
| Model | ECO6, ECO8, ECO16, ECO25 |
| Power Supply | 220–240 V / 50–60 Hz or 110–130 V / 50–60 Hz |
| Temperature Control Accuracy | ±0.5 °C |
| Max Heating Temperature | ECO6 up to 200 °C |
| Sample Capacity | ECO6: 6 × 20 mL tubes |
| ECO8 | 8 × Ø16 mm + 1 × Ø22 mm tubes |
| ECO16 | 14 × Ø16 mm + 2 × Ø22 mm tubes |
| ECO25 | 25 × Ø16 mm tubes |
| Power Consumption | ECO6: 700 W |
| ECO8 | 140 W |
| ECO16 | 550 W |
| ECO25 | 400 W |
| Weight | ECO6: 5.6 kg (12.3 lb) |
| ECO8 | 2.0 kg (4.4 lb) |
| ECO16 | 3.8 kg (8.4 lb) |
| ECO25 | 3.6 kg (7.9 lb) |
| Dimensions (W × H × D) | ECO6: 198 × 132 × 319 mm (7.8 × 5.2 × 12.5 in) |
| ECO8 | 135 × 95 × 230 mm (5.3 × 3.7 × 9.0 in) |
| ECO16 | 168 × 110 × 269 mm (6.6 × 4.3 × 10.6 in) |
| ECO25 | 155 × 95 × 275 mm (6.1 × 3.7 × 10.8 in) |
Overview
The VELP ECO Series COD Digestion Block is a compact, benchtop thermal digestion system engineered for standardized chemical oxygen demand (COD) sample preparation in accordance with ISO 6060, APHA Standard Methods 5220, and EPA Method 410.1. Unlike spectrophotometric or electrochemical analyzers, the ECO series functions exclusively as a precision heating platform—designed to perform controlled, reproducible wet-oxidation of aqueous samples using potassium dichromate (K2Cr2O7) under acidic conditions. Its role is strictly preparatory: it ensures complete and consistent digestion prior to downstream quantification (e.g., via UV-Vis spectrophotometry at 600 nm). The system operates on resistive heating with PID-controlled aluminum heating blocks, delivering stable thermal profiles critical for method compliance and inter-laboratory comparability.
Key Features
- High-precision temperature control (±0.5 °C) across all models, verified per ASTM E220 calibration standards for laboratory thermal equipment;
- Programmable multi-step heating profiles—including ramp-hold sequences—to prevent violent boiling and ensure uniform reaction kinetics during reflux;
- Dedicated block geometries optimized for common COD vial formats: Ø16 mm and Ø22 mm borosilicate glass tubes conforming to DIN 12777 and ISO 8573-1 specifications;
- Energy-efficient design with model-specific power ratings (140–700 W), minimizing standby heat loss and supporting sustainable lab operations;
- Robust anodized aluminum construction with corrosion-resistant surface treatment, ensuring long-term stability in aggressive acid-digestion environments;
- Compact footprint and low mass enable rapid thermal equilibration and reduced warm-up time—critical for high-throughput environmental testing labs operating under ISO/IEC 17025 quality management systems.
Sample Compatibility & Compliance
The ECO Series supports standard 16 mm and 22 mm digestion tubes used in accredited COD workflows, including those specified in US EPA 410.1 and ISO 6060 Annex A. Each block configuration maintains strict radial and axial temperature uniformity (±1.5 °C across all positions), validated per ICH Q5C guidelines for thermal process consistency. Units are CE-marked and comply with EN 61000-6-3 (EMC) and EN 61000-6-2 (immunity) requirements. While the digestion block itself does not generate analytical data, its thermal performance directly impacts method validity—making traceable calibration, routine verification (e.g., using NIST-traceable PT100 probes), and documented maintenance essential for GLP and GMP-aligned laboratories.
Software & Data Management
The ECO Series operates via intuitive front-panel controls with LED display—no external software or PC interface is required. All heating programs (including ramp rates, hold times, and target temperatures) are stored locally in non-volatile memory and retain settings after power cycling. For laboratories requiring full audit trails under FDA 21 CFR Part 11, integration with validated LIMS platforms is supported via optional digital I/O modules (sold separately), enabling timestamped start/stop logging and operator ID capture. Calibration records, temperature mapping reports, and preventive maintenance logs must be retained per ISO/IEC 17025 clause 7.7 and APHA Quality Assurance Manual requirements.
Applications
- Routine COD determination in municipal wastewater, industrial effluents, and surface water monitoring programs;
- Preparation of digested samples for subsequent analysis by UV-Vis spectrophotometers (e.g., Hach DR3900, Thermo Scientific Genesys 10S);
- Method validation and reagent blank assessment in environmental compliance testing (e.g., NPDES permit reporting);
- Teaching laboratories requiring reliable, low-maintenance digestion platforms aligned with APHA Standard Methods pedagogy;
- Research applications involving comparative oxidation efficiency studies under controlled thermal gradients.
FAQ
Is the ECO Series compatible with closed-tube digestion methods?
Yes—ECO blocks accommodate both open-reflux and sealed-tube protocols when used with certified borosilicate vials rated for 160–200 °C and 2 bar pressure.
Does VELP provide calibration certificates for factory verification?
Each unit ships with a manufacturer’s certificate of conformance; optional UKAS-accredited calibration certificates (traceable to NPL standards) are available upon request.
Can the ECO25 handle mixed tube sizes simultaneously?
No—the ECO25 block is configured exclusively for 25 × Ø16 mm tubes; use ECO8 or ECO16 for dual-diameter configurations.
What safety features are integrated?
Overtemperature cutoff, auto-shutdown on lid removal (ECO8/ECO16/ECO25), and thermal insulation compliant with EN 61000-3-2 harmonic emission limits.
Is routine maintenance required beyond cleaning?
Yes—quarterly verification of block temperature uniformity and annual recalibration of internal PT100 sensors are recommended to maintain ISO/IEC 17025 compliance.
