witeg HT-50AX & HT-120AX High-Torque Cantilever Stirrers
| Brand | witeg |
|---|---|
| Origin | Germany |
| Equipment Type | Electric Stirrer |
| Max. Mixing Volume (H₂O) | 40 L / 60 L |
| Speed Range | 50–1,000 rpm |
| Max. Viscosity | 100,000 mPa·s / 150,000 mPa·s |
| Max. Torque at Chuck | 300 N·cm / 500 N·cm |
| Shaft Diameter Max. | 10 mm |
| Timer Range | 0–99 h 59 min |
| Operating Environment | 0–40 °C, ≤80 % RH |
| Power Supply | 120 V AC, 60 Hz or 230 V AC, 50/60 Hz |
| Housing Material | ABS & Aluminum |
| Safety Certifications | CE-compliant with traceable serial number |
| Protection Features | Thermal overload and current-limiting circuitry |
| Dimensions (W×D×H) | 90×180×130 mm / 90×210×130 mm |
| Weight | 3.5 kg / 4.0 kg |
| Packaging Dimensions | 320×300×180 mm |
| Packaging Weight | 5 kg / 8 kg |
Overview
The witeg HT-50AX and HT-120AX are high-torque, digitally controlled cantilever stirrers engineered for reproducible, low-vibration mixing in demanding laboratory environments. Unlike conventional overhead stirrers with belt-driven or gear-reduced transmissions, these models feature a direct-drive brushless DC motor mounted on a rigid aluminum cantilever arm—eliminating mechanical backlash and ensuring precise torque delivery across the full speed range (50–1,000 rpm). The cantilever architecture provides exceptional stability during extended operation, minimizing resonance-induced drift or vessel displacement—critical when handling large-volume batches (up to 60 L of aqueous media) or highly viscous non-Newtonian fluids (up to 150,000 mPa·s). Designed for compliance-critical workflows, each unit carries a unique CE-traceable serial number and integrates dual-layer safety logic: real-time thermal monitoring of motor windings and adaptive current limiting to prevent stall-induced overheating.
Key Features
- Direct-drive brushless DC motor with integrated Jog-Shuttle digital controller—enabling fine-grained speed adjustment via rotary encoder plus momentary push confirmation
- Cantilever support structure fabricated from anodized aluminum and impact-resistant ABS housing—optimized for rigidity and long-term dimensional stability
- Two model variants: HT-50AX (300 N·cm max. torque, 40 L max. volume) and HT-120AX (500 N·cm max. torque, 60 L max. volume)
- Full-range digital speed display with ±1 rpm resolution and automatic zero-speed hold function upon power-on
- Programmable timer (0–99 h 59 min) with audible alert and auto-shutdown on completion or fault detection
- Chromed stainless-steel chuck accommodating shaft diameters up to 10 mm; quick-release mechanism with axial preload adjustment
- Overload protection circuitry compliant with IEC 61000-4-5 surge immunity and EN 60335-1 safety standards
Sample Compatibility & Compliance
These stirrers accommodate a broad spectrum of sample types—including low-conductivity solvents, shear-thinning polymer solutions, cell culture media, and suspension-based pharmaceutical formulations—without introducing mechanical noise or thermal artifacts. The absence of gearboxes or belts prevents lubricant contamination and eliminates maintenance intervals associated with traditional transmission systems. All units are CE-marked per Directive 2014/30/EU (EMC) and 2014/35/EU (LVD), and conform to ISO 17025-relevant operational traceability requirements through individual serial-number registration. Units are compatible with GLP/GMP documentation protocols when paired with validated calibration logs and audit-trail-enabled lab information management systems (LIMS).
Software & Data Management
While standalone operation requires no software, the Jog-Shuttle interface supports external data logging via optional RS-232 or analog 0–10 V output modules (sold separately). When integrated into automated platforms, the stirrer’s digital feedback loop enables synchronization with temperature controllers, pH meters, or peristaltic pumps—facilitating closed-loop reaction control. Firmware updates are performed via secure USB interface, and all configuration parameters—including default speed setpoints, timer presets, and alarm thresholds—are retained after power cycling. Audit trail functionality meets FDA 21 CFR Part 11 requirements when deployed with validated third-party electronic record systems.
Applications
- Batch homogenization of high-viscosity adhesives, coatings, and battery slurries in R&D and pilot-scale manufacturing
- Controlled agitation during dissolution testing (USP Apparatus 2) and viscosity profiling per ASTM D2196
- Long-duration microbial fermentation support where consistent shear input is essential to oxygen transfer efficiency
- Preparation of standardized reference suspensions for particle size analysis (ISO 13320) and rheological benchmarking
- Stirring of heat-sensitive biologics under ambient or chilled conditions, leveraging low-noise motor operation and minimal radiant heating
FAQ
What is the maximum permissible viscosity for continuous operation?
Continuous duty at rated torque is validated for fluids up to 100,000 mPa·s (HT-50AX) or 150,000 mPa·s (HT-120AX) at 25 °C using standard PTFE-coated impellers and laminar flow geometry.
Can the stirrer be operated inside a temperature-controlled chamber?
Yes—provided ambient humidity remains ≤80 % RH and internal chamber temperature stays within 0–40 °C; airflow around the motor housing must not be obstructed.
Is calibration required prior to first use?
No factory calibration is needed; however, users should perform periodic verification of speed accuracy using a certified optical tachometer per ISO/IEC 17025 guidelines.
How is torque overload protection implemented?
Protection combines instantaneous current sensing with thermal modeling of motor winding resistance—triggering immediate speed reduction and visual alarm before reaching critical thermal thresholds.
Are replacement chucks or custom impeller adapters available?
witeg offers a modular accessory kit including collet sets for 6–10 mm shafts, magnetic coupling adapters, and ISO-standard impeller mounting interfaces (DIN 28121).
