VELP OHS 200 Advance Overhead Stirrer

Overview

The VELP OHS 200 Advance Overhead Stirrer is an engineered solution for precision-controlled mixing and dispersion in demanding laboratory environments. Designed according to the principles of Couette flow dynamics and torque-responsive rotational mechanics, it delivers reproducible shear profiles across wide viscosity ranges — from low-viscosity aqueous solutions to highly structured non-Newtonian fluids up to 100,000 mPa·s. Its brushless DC motor architecture, coupled with SpeedServo™ real-time torque compensation, ensures consistent rotational speed regardless of load-induced viscosity fluctuations — a critical requirement for kinetic studies, polymer dissolution, suspension homogenization, and reaction calorimetry workflows. The device complies with IEC 61000-6-2 (immunity) and IEC 61000-6-4 (emission) standards, and its IP54-rated sealed enclosure enables reliable operation in humid, dusty, or chemically exposed benchtop settings typical of QC labs, pilot-scale synthesis, and regulated bioprocessing environments.

Key Features

• Brushless DC motor delivering 200 N·cm maximum torque with stable output across full speed range (50–2000 rpm)
• Two-speed gear modes: Gear 1 (6–400 rpm) optimized for high-torque, low-speed applications; Gear 2 (30–2000 rpm) for high-speed dispersion and emulsification
• SpeedServo™ closed-loop control system dynamically adjusts power delivery to maintain setpoint speed under variable load conditions
• SmartChuck™ one-hand, tool-free impeller mounting system with automatic operational lockout when protective ring is opened
• Integrated vibration sensor with adjustable sensitivity thresholds to detect unstable mounting or vessel resonance and halt rotation immediately
• Real-time torque monitoring (resolution: 1 N·cm) displayed on 3.5″ TFT touchscreen alongside speed, temperature, and elapsed time
• Dual safety architecture: hardware-based overload, overtemperature, and overcurrent cutoffs complemented by software-enforced parameter limits

Sample Compatibility & Compliance

The OHS 200 Advance accommodates standard laboratory vessels including glass beakers (up to 25 L capacity), jacketed reactors, and custom reaction flasks with compatible shaft diameters (6–12 mm). Its Pt100 temperature probe interface supports continuous thermal feedback for exothermic reaction control — enabling automatic speed reduction or process termination upon reaching user-defined thermal thresholds (5–40 °C range). The system meets essential requirements for GLP-compliant documentation: all method parameters (speed, timer, temperature setpoints), event logs (start/stop, alarm triggers, torque excursions), and operator identification (via Ermes Cloud login) are timestamped and exportable. While not intrinsically rated for explosive atmospheres, its IP54 ingress protection satisfies ISO 14644-1 Class 8 cleanroom compatibility when installed with appropriate isolation protocols.

Software & Data Management

Control and data acquisition are supported via two interoperable platforms. VELP Ermes Cloud provides secure Wi-Fi connectivity for remote operation across desktop, tablet, and mobile devices — allowing method activation, real-time parameter adjustment, scheduled run initiation, and PDF report generation without physical access. All cloud sessions adhere to TLS 1.2 encryption and support role-based access control (RBAC), aligning with FDA 21 CFR Part 11 expectations for electronic records and signatures where locally validated. For air-gapped or IT-restricted laboratories, ControllerSoft™ offers equivalent functionality via USB 2.0 interface, enabling offline method programming, data logging (CSV export), and firmware updates. Both platforms store complete audit trails including parameter changes, alarm events, and user actions — supporting traceability in pharmaceutical development, academic research, and contract manufacturing organizations.

Applications

• Kinetic dissolution testing of active pharmaceutical ingredients (APIs) under controlled thermal and shear conditions
• Preparation of uniform colloidal suspensions for nanomaterial characterization (e.g., DLS, TEM sample prep)
• Homogenization of cell culture media containing heat-labile additives (e.g., growth factors, antibiotics)
• Viscosity profiling of polymer melts and hydrogels during crosslinking reactions
• Emulsion formation and stability assessment in cosmetic and food R&D
• Batch-to-batch consistency verification in GMP-compliant intermediate synthesis

FAQ

Does the OHS 200 Advance support ASTM D2196 or ISO 2557-2 viscosity measurement protocols?
It does not function as a viscometer per se, but its torque-stabilized rotation and real-time torque readout enable correlation with apparent viscosity under defined geometry and shear rate — suitable for comparative QC checks aligned with those standards when paired with calibrated impellers.
Can the device operate unattended overnight?
Yes — the programmable timer supports durations up to 99 hours and 59 minutes, and safety interlocks remain fully active during无人值守 operation.
Is calibration of the torque sensor required, and how often?
Torque calibration is factory-performed and traceable to national metrology institutes; no routine recalibration is specified, though annual verification against known mechanical loads is recommended for ISO/IEC 17025-accredited labs.
What impeller types are compatible with SmartChuck™?
Standard ISO-standardized impellers with 6–12 mm cylindrical shanks, including propellers, anchors, paddles, and dissolvers — provided they conform to VELP’s maximum moment-of-inertia specifications (≤ 0.015 kg·m²).
Does the system meet EU RoHS and REACH directives?
Yes — full compliance documentation, including material declarations and SVHC screening reports, is available upon request from VELP technical support.