VELP DK 20 Digester System
| Brand | VELP |
|---|---|
| Origin | Italy |
| Model | DK 20 Digester System |
| Max Temperature | 450 °C |
| Temperature Uniformity | ±0.5 °C |
| Sample Capacity | 20 × 250 mL tubes (Ø42 mm) |
| Heating Block Material | Anodized aluminum |
| Housing Material | Stainless steel |
| Power Consumption | 13% lower than previous generation |
| Interface | 4-button digital control panel with tilted, chemically resistant front display |
| Optional Accessories | COD support rack, KS 1000 fume neutralizer |
Overview
The VELP DK 20 Digester System is a benchtop, microprocessor-controlled wet digestion unit engineered for precise, reproducible sample mineralization in environmental, food, agricultural, and pharmaceutical laboratories. It operates on the principle of open-vessel acid digestion—typically using sulfuric, nitric, or perchloric acids under controlled thermal conditions—to convert organic matrices into soluble inorganic forms suitable for downstream elemental analysis (e.g., by ICP-OES, ICP-MS, or AA spectroscopy). The system employs a high-density anodized aluminum heating block, thermally optimized to deliver exceptional spatial temperature uniformity across all 20 positions. Its closed-loop PID temperature regulation maintains setpoint stability within ±0.5 °C across the full operating range (room temperature to 450 °C), ensuring compliance with method requirements specified in ISO 11047, AOAC 981.10, EPA Method 3050B, and ASTM D5176 for organic carbon and nutrient determination.
Key Features
- Thermally optimized aluminum heating block with reduced height—enhancing heat transfer efficiency while minimizing footprint and energy consumption (13% reduction vs. prior-generation models)
- Stainless steel housing rated for long-term resistance to acid fumes, thermal cycling, and mechanical abrasion per EN 61000-6-3 EMC and IP20 safety classification
- Digital control interface with four tactile buttons and a high-contrast, tilt-mounted LCD display—designed to withstand incidental splashes and thermal exposure during routine operation
- Integrated thermal grid structure beneath the block surface—improving radial heat distribution and protecting both the block and digestion tubes from localized overheating
- Modular accessory compatibility including dedicated COD support racks (for standard 20 × 16 mm or 20 × 22 mm COD vials) and the KS 1000 fume scrubber system for neutralization of NOx, SOx, and HCl vapors
Sample Compatibility & Compliance
The DK 20 accommodates up to twenty 250 mL borosilicate glass digestion tubes (external diameter 42 mm), supporting classical Kjeldahl nitrogen determination (ISO 5983-1), total phosphorus (ISO 6496), and chemical oxygen demand (COD) analysis per ISO 6060 and APHA 5220D. Tube geometry and thermal loading profiles are validated for use with standard VELP-certified digestion vessels and certified reference materials (CRMs) such as NIST SRM 1573a Tomato Leaves. The system meets essential electrical safety requirements per IEC 61010-1 and supports GLP-compliant workflows through traceable temperature logging (when paired with optional VELP DataLogger software and USB interface). For regulated environments, its stable thermal performance facilitates audit readiness under FDA 21 CFR Part 11 when used with compliant data acquisition protocols.
Software & Data Management
While the DK 20 operates as a standalone instrument, it is fully compatible with VELP’s optional DataLogger software suite (v3.2+), enabling time-stamped temperature profile recording, user-defined method storage, and export of CSV-formatted datasets for LIMS integration. The software supports electronic signature capability and audit trail generation—including operator ID, parameter changes, and run completion timestamps—aligning with ALCOA+ data integrity principles. No internal memory or cloud connectivity is embedded; all data handling occurs via secure local PC connection, preserving network isolation requirements common in accredited testing laboratories.
Applications
- Environmental monitoring: Total Kjeldahl nitrogen (TKN), total phosphorus, and COD in wastewater, sludge, and soil extracts
- Food & feed analysis: Crude protein quantification (via N conversion factor), mineral content screening (Ca, Mg, Zn, Cu)
- Agricultural testing: Plant tissue digestion for macro/micronutrient profiling prior to ICP analysis
- Pharmaceutical excipient characterization: Residual catalyst metal determination in API intermediates
- Research applications: Method development for microwave-assisted digestion validation and comparative thermal ramp studies
FAQ
What tube sizes are supported natively on the DK 20?
The standard configuration accepts twenty 250 mL digestion tubes with 42 mm outer diameter; optional COD-specific racks support 16 mm and 22 mm diameter vials.
Is the DK 20 compliant with EPA Method 3050B?
Yes—the system’s temperature accuracy (±0.5 °C), uniformity, and programmable ramp/hold profiles meet the thermal control specifications outlined in EPA SW-846 Method 3050B for acid digestion of sediments and soils.
Can the KS 1000 fume scrubber be used with other VELP digesters?
The KS 1000 is engineered for direct integration with DK series instruments via standardized exhaust port dimensions and flow-rate matching (10–15 L/min); compatibility with non-DK platforms requires third-party ducting adaptation.
Does the DK 20 support gradient temperature programming?
No—it provides single-setpoint temperature control with optional hold-time definition; multi-step ramping requires external timer coordination or integration with VELP’s UDK 162 universal digester platform.
What maintenance is required for long-term thermal accuracy?
Annual verification using NIST-traceable PT100 probe and calibration log review is recommended; cleaning of the aluminum block surface with non-abrasive, acid-resistant cloth prevents thermal emissivity drift.
