HARKE C2 Advanced Surface Tensiometer

Overview

The HARKE C2 Advanced Surface Tensiometer is a benchtop electromechanical instrument engineered for precise, reproducible measurement of surface and interfacial tension using the Wilhelmy plate method—fully compliant with ASTM D971, ISO 6295, ISO 1409, and USP . It employs a high-stability electromagnetic balance force sensor (0–120 g range), eliminating mechanical drift associated with torsion-wire systems. Unlike legacy tensiometers, the C2 integrates an embedded computing platform—replacing external PCs—while maintaining full functional parity with desktop-based control software. Its modular architecture supports both standard Wilhelmy plate and optional Du Noüy ring configurations, with all critical components—including plates and rings—fabricated from corrosion-resistant alloy and manufactured to exact dimensional tolerances per ISO 6295 Annex A. The system operates at ambient temperature by default, with optional Peltier-based heating or external thermostatic jacket integration for controlled-temperature studies (e.g., temperature-dependent γ vs. T profiling).

Key Features

• Electromagnetic balance transducer with ±0.1 mN/m accuracy and 0.01 mN/m display resolution—ensuring traceable, low-drift measurements across repeated cycles.
• Motorized vertical stage with programmable speed (0–10 mm/s) and position resolution of ±0.1 mm over 0–80 mm travel—enabling precise immersion depth control and dwell-time adjustment for kinetic surface adsorption studies.
• Dual-mode visualization: real-time force curve overlay synchronized with numeric tension readout—facilitating immediate validation against theoretical Wilhelmy equation (γ = F / (P·cosθ)) during operation.
• Integrated precision microbalance functionality (0.1 mg readability)—allowing concurrent density determination (via buoyancy method) and mass calibration without auxiliary instrumentation.
• SFT-C1 v3.x software suite featuring GLP-compliant audit trails, role-based user access control, electronic signature support, and 21 CFR Part 11–ready configuration options for regulated environments.
• Standardized Wilhelmy plates and Du Noüy rings manufactured to ISO 6295 geometries; certified dimensional compliance documentation supplied with each unit.

Sample Compatibility & Compliance

The HARKE C2 accommodates aqueous, organic, and surfactant-laden solutions in standard Φ50 mm sample vessels. Its open-stage design permits use with custom cells—including electrochemical or gas-saturated chambers—subject to dimensional constraints. All measurement protocols align with internationally recognized standards: ASTM D971 (petroleum products), ISO 6295 (general liquids), ISO 1409 (plastics), and USP (pharmaceutical formulation characterization). Optional temperature-controlled accessories enable adherence to ISO 1409 Annex B (temperature ramping) and ASTM D1331 (low-surface-tension systems). Device firmware and software are validated per ICH Q9 principles; factory calibration certificates include NIST-traceable reference fluid verification (e.g., pure water at 20 °C: γ = 72.75 mN/m).

Software & Data Management

SFT-C1 v3.x provides a native Windows-compatible interface running on the integrated ARM-based controller. It supports automated method sequencing (A3/A4/A5 per HARKE’s proprietary test package), batch export to CSV/PDF, and time-stamped metadata embedding (operator ID, environmental conditions, calibration status). Raw force-vs.-position datasets are stored in HDF5 format for third-party analysis. Audit logs record all parameter modifications, measurement events, and user logins—exportable as encrypted XML for regulatory review. Optional 21 CFR Part 11 modules include electronic signatures, biometric authentication integration, and immutable archive generation for FDA-regulated QC labs.

Applications

• Quality control of surfactants, detergents, and emulsifiers in chemical manufacturing.
• Formulation development for pharmaceuticals (e.g., micellar solubilization, liposomal stability screening).
• Surface energy assessment of polymer films and coatings prior to adhesion testing.
• Colloidal stability analysis via interfacial tension gradients in oil-water systems.
• Academic research in interfacial thermodynamics, including critical micelle concentration (CMC) determination and Gibbs adsorption isotherm modeling.
• Density profiling of multi-phase systems using combined tensiometric/buoyancy mode.

FAQ

What measurement methods does the HARKE C2 support?
Wilhelmy plate (primary), Du Noüy ring (optional), and density determination via buoyancy—each with dedicated calibration workflows in SFT-C1 software.
Is temperature control included as standard?
No—ambient operation only. Optional accessories include a Peltier-heated stage (±0.1 °C stability) and external thermostatic jacket port for recirculating baths.
How is traceability ensured for regulatory submissions?
Factory calibration uses NIST-traceable reference fluids; SFT-C1 software supports 21 CFR Part 11 configuration with electronic signatures, audit trail export, and secure user authentication.
Can the C2 be integrated into automated lab workflows?
Yes—RS-232 and Ethernet interfaces support SCPI command set integration with LIMS or robotic liquid handlers; OEM SDK available upon request.
What maintenance is required for long-term accuracy?
Annual recalibration recommended; sensor zero-point verification before each session; periodic cleaning of platinum plate/ring with piranha solution (per ISO 6295 Annex C guidelines).