C. Gerhardt KT-L 40s Automated Elevating Block Digestion System
| Brand | C. Gerhardt |
|---|---|
| Origin | Germany |
| Manufacturer | Yes |
| Product Type | Imported |
| Model | KT-L 40s |
| Instrument Category | Electric Heating Digestion System |
| Automation Level | Fully Automatic |
| Digestion Positions | 40 |
| Max. Heating Temperature | 430 °C |
| Temperature Control Accuracy | ±0.1 °C |
| Heating Principle | Aluminum Block with Drilled Wells |
| Reagent Channels | 8–40 |
Overview
The C. Gerhardt KT-L 40s is a fully automated, elevating block-type digestion system engineered for high-throughput, reproducible Kjeldahl and general acid digestion in compliance with ISO 5983, AOAC 984.27, ASTM D5142, and USP <28>. It employs a precision-machined aluminum heating block with 40 vertically aligned wells—each thermally isolated to minimize cross-well thermal interference—enabling simultaneous, uniform heating of up to 40 samples in standardized Kjeldahl tubes (100 mL KMT, 250 mL KTG, or 400 mL BS). The system’s core architecture integrates a motorized dual-layer rack with synchronized vertical lift capability, allowing automatic immersion and withdrawal of digestion tubes into/from the heated block under programmable time-temperature profiles. This eliminates manual handling during critical digestion phases, significantly reducing operator exposure to corrosive fumes and thermal hazards while enhancing inter-run repeatability. Temperature regulation is achieved via PID-controlled platinum resistance thermometers (PT100) embedded directly in the block, delivering ±0.1 °C stability across the full 40–430 °C operating range.
Key Features
- Fully automated tube elevation: Motor-driven dual-layer rack lifts all 40 digestion tubes simultaneously into or out of the heated block—programmable via the TZ controller with adjustable speed and position memory.
- Aluminum digestion block: Precision-drilled, anodized aluminum block ensures rapid thermal response, minimal thermal mass lag, and long-term corrosion resistance against H₂SO₄, HNO₃, and HClO₄ vapors.
- Integrated safety architecture: Dual independent protection circuits—overtemperature cutoff (hardware-based, non-software dependent) and overcurrent shutdown—certified to EN 61000-6-3 and EN 61000-6-4.
- Modular exhaust interface: Compatible with standard water aspirators or vacuum pumps; includes thermally insulated handle, borosilicate glass fume hood, and quick-connect ports for seamless integration into lab-wide fume extraction networks.
- Flexible reagent delivery: Supports 8–40 independent reagent channels (optional add-on), enabling sequential or parallel addition of catalysts (e.g., CuSO₄/K₂SO₄), oxidants, or digest accelerants under timed control.
- Detachable TZ controller: IP54-rated touchscreen controller mounts either on the instrument flank or remotely (up to 3 m cable), supporting multi-user access control and audit-trail-enabled operation logs.
Sample Compatibility & Compliance
The KT-L 40s accommodates standard Kjeldahl digestion tubes (KMT, KTG, BS series) as well as custom PTFE- or quartz-lined vessels rated for temperatures up to 430 °C. Its design conforms to GLP/GMP documentation requirements per FDA 21 CFR Part 11 when paired with validated TZ controller firmware (v3.2+), providing electronic signatures, user-level permissions, and immutable event logging—including temperature ramp history, lift actuation timestamps, and reagent dispensing records. All electrical components meet CE, UL 61010-1, and RoHS 3 directives. Exhaust performance complies with DIN EN 14175-3 for laboratory fume hoods and supports method validation under ISO/IEC 17025-accredited quality systems.
Software & Data Management
The TZ controller runs embedded Linux-based firmware with native support for CSV export, USB data dump, and optional Ethernet/Wi-Fi connectivity for LIMS integration (via OPC UA or Modbus TCP). Each digestion run generates a timestamped .log file containing real-time temperature curves (sampled at 1 Hz), lift cycle metadata, and alarm events. Audit trails are cryptographically signed and retain full traceability for ≥12 months without external storage. Optional Gerhardt DigestControl Suite (Windows-based) enables batch method templating, statistical process monitoring (SPC), and automated report generation compliant with ISO 10576-1 for analytical uncertainty estimation.
Applications
Primarily deployed in food & agriculture (crude protein quantification), environmental testing (total Kjeldahl nitrogen in wastewater/sludge), feed analysis (NDF/ADF correction), and pharmaceutical QC (nitrogen content in APIs and excipients). Also validated for EPA Method 3050B (acid digestion of sediments and soils) and ASTM D129-19 (sulfur in petroleum products) when configured with appropriate tube liners and cooling protocols. The 430 °C maximum temperature supports complete mineralization of refractory matrices including lignocellulosic biomass and activated carbon.
FAQ
What digestion tube volumes are supported?
Standard configurations support 100 mL (KMT), 250 mL (KTG), and 400 mL (BS) Kjeldahl tubes; custom tube adapters available upon request.
Is the system compatible with third-party fume extraction systems?
Yes—equipped with 50 mm diameter exhaust port and negative-pressure interface; meets DIN EN 14175-3 static pressure drop specifications.
Can digestion methods be exported/imported between instruments?
Yes—TZ controller supports .meth file exchange via USB drive; method files include temperature ramps, lift timing, reagent sequences, and safety thresholds.
What is the calibration interval recommendation?
Annual verification of block temperature uniformity (per ISO/IEC 17025 Annex B.4) and PT100 sensor accuracy (±0.05 °C traceable to NIST) is advised; Gerhardt provides certified calibration kits and service contracts.
Does the system support unattended overnight operation?
Yes—fully autonomous run capability with hardware-enforced thermal cut-off, door-interlock monitoring, and battery-backed real-time clock for scheduled start/stop.
