Hach HT200S High-Temperature Digestion System

Overview

The Hach HT200S High-Temperature Digestion System is an engineered solution for rapid, reproducible, and safe chemical oxygen demand (COD), total phosphorus (TP), total nitrogen (TN), and other oxidizable parameter determinations in water and wastewater analysis. It employs Hach’s proprietary High-Speed Digestion (HSD) technology—a thermally optimized, precisely controlled heating protocol that accelerates oxidation reactions under acidic, high-temperature conditions (typically 150–165 °C). Unlike conventional block digesters requiring over two hours, the HT200S achieves complete digestion in just 15 minutes of active heating time, with full cycle completion—including ramp-up, hold, and active cooling—in under 35 minutes. Its integrated Peltier-based cooling module enables rapid thermal quenching post-digestion, minimizing analyte degradation and improving inter-run consistency. Designed for routine use in municipal wastewater laboratories, industrial effluent monitoring facilities, and environmental testing centers, the HT200S complies with core methodological requirements of Standard Methods 5220D (COD), ISO 6060, and EPA Method 410.4—ensuring method traceability and regulatory alignment.

Key Features

• High-speed digestion cycle: 15-minute digestion time at 150 °C or 165 °C, with total processing time ≤35 minutes per batch.
• Integrated thermoelectric (Peltier) cooling system: Reduces sample temperature from 165 °C to <40 °C in <8 minutes—eliminating manual cooling delays and enhancing throughput.
• Automated safety interlock: Chamber door mechanically locks when internal temperature exceeds 80 °C; lock remains engaged until temperature drops below 60 °C—preventing accidental exposure to hot surfaces or pressurized vessels.
• Dual-zone temperature control: Independent calibration and monitoring of heating block and ambient chamber zones ensure uniform thermal distribution across all 25 positions (20 mm × 150 mm tube format).
• Robust construction: Stainless steel housing with corrosion-resistant heating block and sealed electronics—designed for continuous operation in high-humidity laboratory environments.
• Intuitive interface: Backlit LCD display with step-by-step guidance, real-time temperature/time tracking, and programmable method storage for up to 10 user-defined protocols.

Sample Compatibility & Compliance

The HT200S accommodates standard 16-mm or 20-mm borosilicate glass digestion tubes (e.g., TNTplus vials, LCK vials, or custom 150-mm tall tubes) and supports both open-reflux and closed-vessel digestion chemistries. It is validated for use with Hach TNTplus pre-mixed reagent vials (e.g., TNT820, TNT821, TNT822) and compatible with alternative reagent systems meeting APHA/AWWA/WEF Standard Methods specifications. The system meets IEC 61010-1:2010 safety standards for laboratory electrical equipment and conforms to CE marking requirements. Its operational parameters align with GLP-compliant workflows, supporting audit-ready documentation when paired with Hach’s DR3900 or DR6000 spectrophotometers equipped with 21 CFR Part 11-compliant software (e.g., Hach Unipoint or LabStation).

Software & Data Management

While the HT200S operates as a standalone hardware platform without embedded data logging, it is fully interoperable with Hach’s ecosystem of analytical instruments and informatics tools. When used with Hach spectrophotometers (DR3900, DR6000), the digestion status—start time, set temperature, duration, and completion flag—is automatically timestamped and transferred via RS232 or USB to instrument firmware. Measurement data, including absorbance values, calculated concentrations, and QC metrics (e.g., blank drift, replicate standard deviation), are stored with full audit trail functionality in Hach LabStation software. This integration satisfies FDA 21 CFR Part 11 requirements for electronic records and signatures, including user authentication, change history, and non-erasable event logs.

Applications

• Routine COD analysis in municipal wastewater treatment plants (influent, effluent, sludge supernatant).
• Industrial process water and discharge monitoring (e.g., food & beverage, pharmaceutical, textile, and chemical manufacturing).
• Regulatory compliance testing per ISO 6060, DIN 38409-H41, and China’s HJ 828-2017 (equivalent to APHA 5220D).
• Research and method development involving rapid oxidation kinetics for emerging contaminants (e.g., microplastics-associated organics, pharmaceutical residues).
• Quality control of digested samples prior to ICP-MS or IC analysis for trace metal or anion speciation.

FAQ

What digestion methods is the HT200S validated for?
The HT200S is validated for Standard Methods 5220D (COD), ISO 6060 (COD), EPA Method 410.4 (COD), and Hach’s internal protocols for total phosphorus (ISO 6878) and total Kjeldahl nitrogen (ISO 5663).
Can the HT200S be used with non-Hach reagents?
Yes—provided reagents meet dimensional compatibility (tube diameter/length), thermal stability up to 165 °C, and acid concentration limits specified in ASTM D1252 or ISO 6060.
Does the HT200S include data export capability?
No standalone data export; however, full integration with Hach spectrophotometers enables automatic transfer of digestion metadata and measurement results into compliant LIMS or LabStation environments.
Is maintenance required for the Peltier cooling system?
The solid-state Peltier module is maintenance-free; periodic inspection of heatsink fins and ambient airflow clearance is recommended every 6 months.
How does the HT200S ensure temperature uniformity across all positions?
Each unit undergoes factory calibration using NIST-traceable RTD probes; block uniformity is verified to ±1.5 °C across all 25 positions at 150 °C and 165 °C setpoints.