Yoyilab NDJ-5S Digital Rotational Viscometer

Overview

The Yoyilab NDJ-5S Digital Rotational Viscometer is a benchtop instrument engineered for precision viscosity measurement of Newtonian and mildly non-Newtonian fluids using the principle of Couette flow rheometry. It operates by rotating a calibrated spindle (spindle geometry defined per ASTM D2196 and ISO 2555) at a fixed angular velocity within a sample; the torque required to maintain that rotation is linearly related to the fluid’s dynamic viscosity. Designed for routine quality control and R&D applications in regulated and non-regulated environments, the NDJ-5S delivers traceable, reproducible results across a 10⁴-viscosity range (10–10⁵ mPa·s) with resolution down to 0.01 mPa·s. Its rigid one-piece chassis, integrated leveling system with bubble level and height-adjustable support column ensure mechanical stability during extended measurements—critical for minimizing drift in time-dependent viscosity assessments.

Key Features

• High-resolution 3.5″ IPS color LCD display with dual-language UI (English/Chinese), enabling real-time visualization of viscosity, spindle number, rotational speed, torque %, temperature (when probe is connected), and maximum measurable viscosity for the selected spindle/speed combination
• Microprocessor-based control system with optimized sampling rate ensures accurate torque acquisition and stable signal processing under varying load conditions
• Four standard spindle configurations (#1–#4) paired with four discrete rotational speeds (6, 12, 30, 60 rpm) yield 16 distinct measurement combinations—enabling method flexibility without hardware reconfiguration
• Three operational modes: Auto-Stabilization (measurement terminates automatically upon signal convergence), Timed Mode (user-defined duration up to 99 minutes), and Auto-Scan (intelligent recommendation of optimal spindle/speed based on preliminary torque feedback)
• Onboard data storage for 50 complete measurement records, including timestamp, spindle ID, speed, viscosity value, temperature, torque %, and measurement duration
• Dual communication interfaces (USB 2.0 and RS-232) support direct connection to printers or laboratory PCs for raw data export in CSV-compatible format—facilitating integration into LIMS or Excel-based analysis workflows
• Optional temperature probe input (PT100-compatible) enables simultaneous viscosity–temperature profiling in compliance with ASTM D1074 and ISO 7305 test protocols

Sample Compatibility & Compliance

The NDJ-5S accommodates low-to-medium viscosity liquids typical of adhesives (solvent-based), coatings, inks, food emulsions, pharmaceutical suspensions, polymer solutions, and fine chemical intermediates. Its spindle geometry and shear rate profile align with industry-standard test methods including ASTM D1200 (Ford Cup), ASTM D2196 (Brookfield-type viscometry), and ISO 2555. While not certified for GMP environments out-of-the-box, the instrument supports audit-ready operation when used with validated procedures: all stored measurements include immutable metadata (date/time, operator ID if entered manually, configuration parameters), and exported data retains full traceability. Optional temperature monitoring extends applicability to viscosity-temperature coefficient (VTC) determination per ASTM D341.

Software & Data Management

No proprietary software is bundled; however, the NDJ-5S transmits ASCII-formatted data packets via USB or RS-232, compatible with generic terminal emulators (e.g., Tera Term), LabVIEW drivers, or custom Python/Excel VBA scripts. Each transmission includes: date, time, spindle number, rpm, measured viscosity (mPa·s), temperature (°C), torque (%), and elapsed measurement time. For regulated labs, users may implement 21 CFR Part 11-compliant data handling through third-party acquisition platforms—provided electronic signatures, audit trails, and user access controls are externally managed. The device itself maintains no user roles or password protection; configuration changes require physical button input, ensuring procedural integrity in shared-lab settings.

Applications

• QC release testing of solvent-borne adhesives and sealants where batch-to-batch consistency is governed by viscosity limits (e.g., ISO 2555 pass/fail thresholds)
• Formulation development of water-based paints and architectural coatings, particularly during thinning trials or resin selection studies
• Routine monitoring of fermentation broths and protein solutions in bioprocessing labs, where viscosity trends correlate with cell density or aggregation state
• Stability assessment of edible oils and dairy emulsions across shelf-life studies, often combined with temperature ramping via external bath
• Educational use in university materials science and chemical engineering laboratories for introducing fundamental rheological concepts (shear stress vs. shear rate, Newtonian behavior validation)

FAQ

What spindle geometries are included with the NDJ-5S, and can they be interchanged with other Brookfield-style instruments?
The NDJ-5S ships with spindles #1–#4 conforming to ISO 2555 Annex A dimensions. While mechanically compatible with many standard L-type spindles, calibration constants differ from Brookfield DV series—direct substitution without recalibration is not recommended.
Is temperature control built-in, or does it require external equipment?
The NDJ-5S has no integrated heating/cooling system. Temperature measurement requires an optional PT100-compatible probe connected via the rear panel input; active thermal regulation must be achieved using external circulating baths or Peltier stages.
Can measurement data be exported in SI units only, without legacy CGS conversions?
Yes—the instrument reports viscosity exclusively in millipascal-seconds (mPa·s), the SI-derived unit accepted by ISO and ASTM. No centipoise (cP) output is generated; 1 mPa·s = 1 cP numerically, but unit labeling remains strictly SI-compliant.
Does the NDJ-5S support GLP-compliant record keeping?
It provides essential metadata for GLP documentation (timestamp, configuration, raw values), but lacks electronic signature capability, role-based access, or automated audit trail generation. Full GLP alignment requires supplementary procedural controls and external data management systems.