Shengaohua SH-10S V10 Single-Channel Single-Control COD Reflux Digestion System

Overview

The Shengaohua SH-10S V10 Single-Channel Single-Control COD Reflux Digestion System is a dedicated benchtop instrument engineered for precise, reproducible chemical oxygen demand (COD) sample preparation in compliance with HJ 828–2017, the Chinese national standard for COD determination by the dichromate method. It operates on the principle of closed-loop reflux digestion under controlled thermal conditions, where aqueous samples are oxidized with potassium dichromate in strong sulfuric acid medium at elevated temperatures (typically 150–165 °C) for a defined duration. The system employs a high-stability aluminum heating block with individually addressable temperature control per channel, ensuring uniform thermal distribution across all 10 digestion positions. Its modular architecture supports both research-grade method development and routine environmental QA/QC workflows in accredited laboratories.

Key Features

• Independent single-channel temperature control per digestion position — eliminates cross-channel thermal interference and enables method optimization for heterogeneous sample matrices;
• Integrated 7-inch capacitive touchscreen interface with intuitive Chinese-language menu navigation, real-time temperature/time display, and programmable timer (1–999 minutes, 0.1-second resolution);
• Dual cooling configuration: user-selectable forced-air convection (with high-volume enclosed fan assembly) or external water-cooling jacket — ensures consistent condensate return and prevents reagent loss during extended reflux cycles;
• Automated operational sequence: one-touch start, individual channel activation, audible completion alert, and automatic power cutoff upon timer expiration;
• Energy-efficient design with low thermal radiation profile and compact footprint (≤0.45 m²), suitable for space-constrained analytical labs;
• Robust mechanical construction: die-cast aluminum heating block, corrosion-resistant housing, and reinforced PTFE-coated digestion tube holders;
• Compliant with ISO/IEC 17025 documentation requirements — full traceability of setpoints, actual temperatures, and runtime logs via internal memory (exportable via USB).

Sample Compatibility & Compliance

The SH-10S accommodates standard 250 mL borosilicate glass digestion tubes and is validated for use with domestic and industrial wastewater, surface water, effluent streams, and pretreated sludge extracts. It meets the physical and procedural specifications outlined in HJ 828–2017, including minimum reflux time (120 minutes), temperature stability (±1 °C over full cycle), and volumetric precision. While not certified to ASTM D1252 or ISO 6060, its performance parameters align with the repeatability thresholds stipulated in those standards: ≤5.0% RSD for KHP reference solution (500 mg/L COD) and ≤8.0% RSD for spiked industrial wastewater matrices. The instrument’s thermal uniformity and timer accuracy support GLP-compliant data generation when paired with validated wet chemistry protocols.

Software & Data Management

The embedded firmware provides local storage of up to 1,000 digestion records, each timestamped with start/end times, target/actual temperatures, and user ID (via optional login module). Data export is supported via USB 2.0 port in CSV format for integration into LIMS or Excel-based QA review. Though the system does not implement FDA 21 CFR Part 11 electronic signature controls natively, audit trail functionality (including parameter change history and operator log) can be enabled through firmware update (v2.3+). All temperature and timing parameters are factory-calibrated and traceable to NIM (National Institute of Metrology, China) standards.

Applications

• Regulatory wastewater monitoring per municipal discharge permits and provincial environmental protection bureau mandates;
• Process control in electroplating, dyeing & finishing, papermaking, and food processing facilities;
• Method validation and interlaboratory comparison studies in third-party testing organizations;
• Teaching and research applications in university environmental engineering and analytical chemistry laboratories;
• Preparatory digestion for subsequent spectrophotometric (e.g., DR6000) or titrimetric COD quantification;
• Supporting ISO 14001-certified environmental management systems through documented, repeatable sample conditioning.

FAQ

Is the SH-10S compatible with international COD standards such as ISO 6060 or ASTM D1252?
It is designed primarily for HJ 828–2017 compliance. While its thermal and timing specifications meet the technical prerequisites of ISO 6060 and ASTM D1252, formal certification under those standards requires additional validation per laboratory SOPs.

Can digestion time and temperature be adjusted independently for each of the 10 channels?
No — the SH-10S features single-channel *per-position* control, meaning each of the 10 slots maintains its own setpoint, but all share the same global timer. Independent timing per channel is not supported.

What maintenance is required for long-term reliability?
Annual verification of temperature sensor calibration and fan airflow rate is recommended. Cleaning of the aluminum block surface and condenser ports with isopropyl alcohol every 200 runs prevents residue buildup and ensures thermal contact integrity.

Does the instrument include data export capability for regulatory reporting?
Yes — digestion logs (including temperature profiles and timestamps) are exportable in CSV format via USB, supporting traceability for internal QA audits and external accreditation reviews.