ShengAohua 6B-6(V9) COD Digestion Block

Overview

The ShengAohua 6B-6(V9) COD Digestion Block is a benchtop rapid digestion system engineered for precise, reproducible thermal pretreatment of aqueous samples prior to chemical oxygen demand (COD), total phosphorus (TP), total nitrogen (TN), copper, and hexavalent chromium quantification. It operates on the principle of controlled conductive heating via a high-thermal-conductivity aluminum block, ensuring uniform temperature distribution across all six digestion positions. Designed in strict alignment with standard methods—including ISO 6060 (water quality—determination of chemical oxygen demand), EPA Method 410.4, and HJ 828–2017 (Chinese Environmental Protection Standard for COD determination)—the unit delivers stable thermal profiles within ±0.5 °C of setpoint, critical for minimizing inter-laboratory variability in redox-based digestions. Its closed-tube configuration prevents reagent loss and cross-contamination while enabling safe handling of aggressive oxidants such as potassium dichromate–sulfuric acid mixtures under reflux conditions.

Key Features

• Single integrated aluminum heating block with optimized thermal mass and surface emissivity for rapid, homogeneous heat transfer—achieving target temperature (e.g., 165 °C) in ≤10 minutes.
• Six parallel digestion positions accommodating standard 17 mL borosilicate glass or quartz digestion tubes; compatible with both open-reflux and sealed-vessel protocols.
• Intuitive Chinese-language blue-backlit LCD interface with real-time display of set temperature, actual temperature, remaining time, and operational status.
• Dedicated 4-key timer panel supporting independent start/stop functions per channel—enabling staggered sample loading without manual intervention.
• Pre-programmed digestion curves for COD (165 °C/120 min), TP (120 °C/30 min), TN (125 °C/30 min), Cu (95 °C/15 min), Cr(VI) (100 °C/10 min), and custom method development.
• User-modifiable temperature/time profiles with non-volatile memory retention; supports incremental setting resolution of 1 °C and 1 min.
• Hardware-level overtemperature protection circuitry that automatically de-energizes the heater if sensor feedback exceeds preset safety thresholds—ensuring compliance with IEC 61010-1 electrical safety requirements.
• Injection-molded housing constructed from flame-retardant, corrosion-resistant thermoplastic (UL94 V-0 rated), rated for continuous operation at ambient temperatures from –5 °C to 45 °C.

Sample Compatibility & Compliance

The 6B-6(V9) accommodates standard 17 mL digestion vials used in accredited environmental testing laboratories. Its thermal stability and repeatability meet the performance criteria outlined in ISO/IEC 17025:2017 for method validation of digestion steps in water analysis workflows. The instrument supports full traceability when paired with laboratory information management systems (LIMS) through manual log entry of batch IDs, operator codes, and digestion parameters. While not inherently 21 CFR Part 11 compliant (as it lacks electronic signature or audit trail functionality), its deterministic timer and calibrated temperature control support GLP-aligned documentation practices. It is routinely deployed in facilities certified to ISO 14001 and aligned with national regulatory frameworks including China’s HJ series standards and EU Water Framework Directive (WFD) monitoring protocols.

Software & Data Management

The 6B-6(V9) operates as a standalone hardware platform with no embedded firmware update capability or PC connectivity. All parameter inputs—temperature setpoints, timer durations, and curve selections—are entered directly via membrane keypad and retained in EEPROM. Operators record digestion metadata (sample ID, date/time, method code, observed endpoint color or absorbance) manually in hard-copy lab notebooks or digital LIMS entries. For laboratories requiring automated data capture, integration is achieved externally using USB-connected thermal printers or barcode scanners synchronized with sample tracking software. No proprietary drivers or cloud services are required or supported.

Applications

This digestion block serves as a core pretreatment module in environmental quality control labs performing routine wastewater effluent monitoring, drinking water source assessment, industrial discharge verification, and research-scale method development. It is validated for use in municipal wastewater treatment plants (WWTPs), pulp & paper mills (for chloride interference mitigation), pharmaceutical manufacturing sites (cleaning validation), textile dyeing facilities (COD load profiling), and food & beverage processing plants (organic load estimation). Its robust design ensures consistent performance across seasonal ambient fluctuations—from cold northern winters to humid southern summers—without recalibration.

FAQ

What digestion standards does the 6B-6(V9) support?
It is configured to meet ISO 6060, EPA 410.4, ASTM D1252, and China’s HJ 828–2017 for COD; HJ 670–2013 for TP; and HJ 636–2012 for TN.
Can it be used for mercury digestion or microwave-assisted protocols?
No—it is designed exclusively for conductive heating of closed-tube, low-pressure wet-chemical digestions; it does not support high-pressure or microwave energy delivery.
Is calibration traceable to national standards?
Yes—temperature sensors are factory-calibrated against NIM (National Institute of Metrology, China)-certified references; users may perform periodic verification using PT100 reference probes.
What maintenance is required?
Annual visual inspection of heating block surface integrity, cleaning of vent channels with compressed air, and verification of keypad responsiveness; no consumables or scheduled servicing intervals are specified.
Does it include digestion reagents or vials?
No—reagents (e.g., COD digestion solution, catalyst, sulfuric acid) and 17 mL digestion tubes must be procured separately per analytical method requirements.