Brookfield NDJ-5S Digital Rotational Viscometer

Overview

The Brookfield NDJ-5S Digital Rotational Viscometer is a precision-engineered instrument designed for routine viscosity measurement of Newtonian and mildly non-Newtonian fluids in quality control, R&D, and production environments. Based on the classical Couette principle—where torque required to rotate a spindle immersed in a fluid at a defined angular velocity is directly proportional to its dynamic viscosity—the NDJ-5S delivers reliable, repeatable results across industrial sectors including edible oils, coatings, pharmaceutical suspensions, food emulsions, and adhesive formulations. Unlike capillary or falling-ball viscometers, this rotational system enables direct readout of absolute viscosity (in mPa·s or cP) without empirical calibration against reference standards. Its robust mechanical architecture, combined with a microprocessor-regulated synchronous motor, ensures stable rotational speed regardless of local mains frequency fluctuations (50 Hz or 60 Hz), eliminating a common source of drift in analog viscometers used in global laboratories.

Key Features

• Four standard LV spindles (#1–#4) optimized for low-to-moderate viscosity ranges (10–10⁵ mPa·s), enabling broad fluid coverage without manual spindle recalibration
• Fixed-speed operation at four discrete rotational settings: 6, 12, 30, and 60 rpm—selected via mechanical dial for operational simplicity and long-term stability
• Analog pointer display with dual-scale graduation (torque % and viscosity units), offering immediate visual interpretation without software dependency
• Integrated temperature-compensated torque sensing mechanism, minimizing thermal drift during extended measurements
• Self-contained design requiring only standard AC power input—no external controllers, PC interfaces, or proprietary drivers needed
• Compliance-ready mechanical construction suitable for GLP-aligned documentation workflows; all critical components traceable per ISO 9001 manufacturing protocols

Sample Compatibility & Compliance

The NDJ-5S accommodates samples in standard 600-mL sample cups or cylindrical containers with minimum depth ≥85 mm and inner diameter ≥65 mm—compatible with ASTM D2196, ISO 2555, and GB/T 265 test geometries. It supports both ambient and controlled-temperature testing when paired with optional water baths or Peltier-based temperature jackets (not included). While not equipped with audit-trail or electronic signature capabilities, its analog output and manual recording workflow align with basic GLP documentation requirements where digital data integrity is managed externally. For regulated environments requiring 21 CFR Part 11 compliance, users may integrate manual log entries into validated LIMS platforms using standardized observation templates.

Software & Data Management

The NDJ-5S operates as a standalone instrument with no embedded firmware or USB/RS-232 connectivity. All viscosity values are recorded manually from the analog scale, supporting paper-based SOP execution in facilities where digital instrumentation validation is not mandated. Users may digitize readings using standardized Excel-based templates aligned with ISO/IEC 17025 uncertainty budgeting guidelines. Optional accessories—including calibrated reference oil sets (certified per ASTM D445) and spindle calibration certificates—facilitate periodic verification in accordance with internal QA procedures.

Applications

• Quality assurance of vegetable oils, margarines, and shortening during refining and packaging
• Routine QC of architectural paints, varnishes, and ink formulations pre- and post-dispersion
• Batch release testing of oral suspensions, topical gels, and syrup vehicles in pharmaceutical manufacturing
• Process monitoring of starch pastes, dairy concentrates, and fruit purees in food processing lines
• Adhesive formulation development—assessing open time, wet tack, and shear-thinning behavior under fixed-shear conditions
• Educational labs demonstrating fundamental rheological concepts including Newtonian flow, viscosity-temperature dependence, and spindle geometry effects

FAQ

What viscosity range does the NDJ-5S cover?

The NDJ-5S measures dynamic viscosity from 10 mPa·s to 10⁵ mPa·s (cP) using spindles #1 through #4 at 6–60 rpm.
Is temperature control built into the instrument?

No—temperature regulation requires an external bath or jacket; the NDJ-5S itself contains no heating or cooling elements.
Can it measure non-Newtonian fluids accurately?

It provides apparent viscosity values at discrete shear rates; for full rheological profiling (e.g., yield stress, flow curves), a programmable rheometer with variable shear rate capability is recommended.
Does the NDJ-5S comply with FDA 21 CFR Part 11?

Not natively—it generates analog outputs only; electronic records must be created externally and governed by site-specific validation protocols.
How often should spindle calibration be performed?

Annual verification against NIST-traceable reference oils is recommended, or per internal QA schedule aligned with ISO/IEC 17025 Clause 6.4.10.