KEM CHD-502N Automated Multi-Sample Handler for Oscillating U-Tube Density Meters

Overview

The KEM CHD-502N is an automated multi-sample handler engineered exclusively for integration with KEM’s oscillating U-tube digital density meters—including the DA-6xx series (e.g., DA-650, DA-645, DA-640). It operates on the principle of resonant frequency measurement: when a U-shaped glass tube filled with sample liquid undergoes controlled mechanical oscillation, its natural frequency shifts proportionally to the sample’s mass and volume—enabling highly accurate, temperature-compensated density determination per ISO 12058-1, ASTM D4052, and USP . The CHD-502N extends this core metrology by eliminating manual handling bottlenecks. Designed for high-throughput laboratories performing routine quality control, raw material verification, or formulation consistency checks, it enables unattended sequential analysis of up to 30 liquid samples without operator intervention—while maintaining traceable thermal equilibration and metrological integrity across all measurements.

Key Features

• Fully automated liquid handling cycle: aspiration, dispensing, rinsing (with solvent-compatible wash protocol), and nitrogen-assisted drying—all programmable per sample or batch.
• Dual-mode fluid actuation system: integrated vacuum-pressure pump delivers precise aspiration from low-viscosity solvents (e.g., ethanol, water) to high-viscosity liquids up to 50,000 mPa·s (e.g., lubricants, polymer solutions, syrups), ensuring complete tube filling without bubble entrapment.
• Sample recovery capability: pressurized discharge returns residual sample to its original vial—critical for precious, regulated, or hazardous materials under GLP/GMP workflows.
• Thermal synchronization: communicates real-time bath temperature data to the host densimeter, enabling dynamic temperature stabilization prior to each measurement—minimizing thermal drift and ensuring compliance with ISO 5725 repeatability requirements.
• Energy-efficient operation: auto-power-down triggers after final sample analysis and system purge; standby power draw <5 W.
• Benchtop footprint optimized for ISO 17025-accredited lab layouts: compact dimensions (582 × 445 × 392 mm) accommodate standard fume hoods or laminar flow workstations.

Sample Compatibility & Compliance

The CHD-502N supports aqueous, organic, and halogenated liquids compatible with borosilicate glass capillary systems. It accommodates standard 20 mL screw-cap glass vials (e.g., Kimble Chase, Wheaton), with optional adapters for alternative container formats. All wetted components—including tubing, valves, and pump seals—are chemically resistant to common laboratory solvents (acetone, methanol, chloroform, toluene) and non-oxidizing acids/bases. The system meets IEC 61010-1 safety standards for laboratory equipment and is designed to support audit-ready documentation per FDA 21 CFR Part 11 when paired with KEM’s compliant DA-6xx firmware and PC software. It complies with ISO/IEC 17025 clause 5.4.2 regarding automated instrument calibration traceability and environmental monitoring.

Software & Data Management

Controlled via KEM’s proprietary Density Manager™ software (v4.2+), the CHD-502N supports method-based sequencing, including variable rinse cycles, dwell times, and temperature ramp profiles. Each measurement log includes timestamp, vial ID, ambient temperature, bath temperature, density value, standard deviation, and pass/fail flags against user-defined specification limits. Raw oscillation frequency data and temperature curves are exportable in CSV and XML formats for third-party statistical process control (SPC) platforms. Audit trails record all operator actions, parameter changes, and system status events—with immutable timestamps aligned to NIST-traceable RTC.

Applications

• Pharmaceutical excipient QC: density verification of glycerin, propylene glycol, PEGs, and sterile aqueous formulations per USP monographs.
• Petrochemical QA: API gravity, biodiesel blend verification (ASTM D7467), and hydrocarbon fraction density profiling.
• Food & beverage R&D: sugar concentration (Brix) correlation, alcohol content estimation, and syrup consistency validation.
• Chemical manufacturing: catalyst solution density tracking, monomer purity screening, and reaction mixture density monitoring.
• Academic research: high-precision density databases for thermophysical property modeling (e.g., excess molar volume, partial molar properties).

FAQ

Is the CHD-502N compatible with non-KEM density meters?
No—it is hardware- and firmware-locked to KEM DA-6xx-series oscillating U-tube densimeters via proprietary RS-232/CAN bus interface.
Can the system handle corrosive samples such as concentrated HCl or NaOH?
Only with validated chemical compatibility testing; standard configuration uses fluoropolymer seals—custom Hastelloy or sapphire-wetted options require factory consultation.
Does the CHD-502N support 21 CFR Part 11 electronic signatures?
Yes, when used with KEM DensManager™ v4.5+ and configured with Windows Active Directory authentication and role-based access control.
What maintenance intervals are recommended for the vacuum-pressure pump?
Pump oil replacement every 12 months or 2,000 operational hours; full valve assembly inspection recommended annually per ISO/IEC 17025 preventive maintenance schedule.
How is temperature uniformity verified across all 30 sample positions?
KEM provides a certified calibration certificate documenting thermal gradient mapping (±0.02 °C max deviation at 20 °C and 40 °C setpoints) using NIST-traceable PT100 probes.