Hanuo WS-3 Ubbelohde Viscometer Constant-Temperature Bath

Overview

The Hanuo WS-3 Ubbelohde Viscometer Constant-Temperature Bath is a precision-engineered thermal platform designed exclusively for capillary viscometry in accordance with ASTM D445, ISO 3104, and USP <911>. It provides thermally stable immersion conditions for Ubbelohde-type suspended-level viscometers used in the characterization of Newtonian and near-Newtonian liquids—including polymer solutions, pharmaceutical solvents, synthetic resins, and biopolymer formulations. Unlike general-purpose water baths, the WS-3 integrates a rigid, optically transparent acrylic bath chamber, calibrated PID temperature control, and dedicated mechanical fixtures that ensure strict vertical alignment of capillary viscometers—critical for minimizing hydrostatic head error and achieving repeatability ≤0.2% RSD across replicate runs.

Key Features

• High-stability thermal environment: ±0.05 °C temperature uniformity over full 30 L working volume at setpoints from ambient to 80 °C
• Optically clear, chemically resistant acrylic bath chamber enabling real-time visual monitoring of capillary flow and meniscus positioning
• Dedicated Ubbelohde viscometer holder with micrometer-adjustable verticality compensation (±0.1° fine-tuning)
• Internal recirculation system with low-turbulence impeller ensuring homogeneous thermal distribution without surface agitation
• Triple-resolution digital display (0.1 °C / 0.01 °C / 0.001 °C selectable), supporting both routine QC and high-accuracy method validation
• Over-temperature and over-current protection circuitry compliant with IEC 61010-1 safety standards
• Compact footprint (W × D × H: 360 × 360 × 620 mm) optimized for benchtop integration in GLP-compliant analytical laboratories

Sample Compatibility & Compliance

The WS-3 accommodates up to four Ubbelohde viscometers simultaneously—each secured in independent, height-adjustable clamps aligned to ASTM D445’s requirement for “vertical orientation within ±0.5°.” Its 4 × Ø65 mm aperture configuration supports standard viscometer diameters (e.g., Cannon-Fenske, Ubbelohde DIN 51562, and ASTM D445 Type I–IV). The bath is compatible with water, silicone oil, and ethylene glycol–water mixtures (viscosity < 50 cSt at operating temperature), with material compatibility validated per ISO 10993-5 for non-cytotoxic contact surfaces. All thermal performance data are traceable to NIM (National Institute of Metrology, China)–certified reference probes, and the unit meets CE marking requirements for laboratory equipment under Directive 2014/30/EU (EMC) and 2014/35/EU (LVD).

Software & Data Management

The WS-3 operates as a standalone analog-controlled instrument with no embedded software or connectivity ports—intentionally designed to eliminate electromagnetic interference with sensitive viscometer timing electronics and to support audit-ready manual data recording workflows. Temperature setpoints and stability metrics are recorded directly on paper log sheets or integrated into LIMS via external PT100-compatible data loggers (e.g., Omega OM-DAQPRO-5300). For regulated environments (FDA 21 CFR Part 11, EU Annex 11), users may pair the bath with validated electronic notebooks or chromatography data systems (CDS) that capture timestamped temperature readings alongside viscosity run metadata. Calibration certificates include as-found/as-left data, uncertainty budgets (k = 2), and compliance statements against ISO/IEC 17025:2017 Clause 6.5.

Applications

• Determination of intrinsic viscosity ([η]) and molecular weight of polyethylene terephthalate (PET), polycarbonate, and polyacrylonitrile in concentrated sulfuric acid or phenol–tetrachloroethane solvents
• Batch release testing of injectable polymer-based drug delivery vehicles (e.g., PLGA microspheres, hyaluronic acid gels) per USP <911>
• Quality control of industrial lubricants and transformer oils per ASTM D445 and IEC 60296
• Research-scale rheological screening of cellulose derivatives (e.g., methylcellulose, hydroxypropyl methylcellulose) in aqueous media
• Viscosity grading of natural resins (rosin, shellac) and synthetic alkyd resins used in coatings and adhesives

FAQ

Is the WS-3 suitable for use with dilution viscometers requiring temperature ramping?
No—the WS-3 is a heating-only bath with fixed-setpoint operation and lacks programmable ramping capability. For dynamic temperature profiling, consider the Hanuo WS-2G or WS-4G models equipped with dual-range PID controllers and RS-485 Modbus interfaces.

Can the bath be operated with silicone oil at 150 °C?
No—the maximum rated temperature is 80 °C. Operation above this limit voids warranty and risks acrylic chamber deformation and seal degradation. For elevated-temperature applications (up to 200 °C), refer to the WS-2 or WS-4 series, which feature stainless-steel tanks and high-temp circulation pumps.

Does the unit include calibration documentation?
Yes—each WS-3 ships with a factory calibration certificate (traceable to NIM), including temperature uniformity mapping at three depths (10 cm, 20 cm, 30 cm) and stability verification at 25 °C, 40 °C, and 60 °C per ISO 17025 procedures.