English Product Name

Overview

The Jihepu NDJ-5S Digital Rotational Viscometer is a precision-engineered instrument designed for routine and quality control viscosity measurements of Newtonian and mildly non-Newtonian fluids in laboratory and production environments. Based on the Couette principle—where torque generated by fluid resistance to rotation of a spindle immersed in the sample is measured—the NDJ-5S delivers stable, reproducible results across a wide dynamic range (1–100,000 mPa·s). Its gearless, high-subdivision stepper motor ensures accurate, jitter-free rotational speeds independent of line frequency fluctuations—a critical feature for metrological consistency in variable power grid conditions. The instrument is calibrated across its entire scale using certified standard oils and supports full-range linear correction, enabling traceable measurements compliant with internal QC protocols and foundational ISO 2555 and ASTM D2196 practices.

Key Features

• Gearless four-speed drive system (6, 12, 30, 60 rpm) eliminates mechanical backlash and ensures long-term speed stability.
• Real-time LCD display with blue backlight shows dynamic viscosity (mPa·s), rotational speed (rpm), % torque loading, and maximum measurable viscosity for the selected spindle/speed combination—enabling immediate operational verification.
• Patented multi-sampling-per-revolution algorithm overcomes traditional single-sample limitations common in entry-level rotational viscometers, improving data density and statistical robustness for time-dependent analysis.
• Integrated overload detection with audible alert prevents transducer damage and ensures measurement integrity when viscosity exceeds spindle-specific limits.
• Switching-mode power supply (110–220 V, 50/60 Hz) provides wide-input compatibility and superior noise immunity in shared lab electrical environments.
• Direct stepper motor coupling eliminates belt or gear wear, delivering silent operation, extended service life, and zero maintenance-driven drift.

Sample Compatibility & Compliance

The NDJ-5S accommodates a broad spectrum of liquid samples—from low-viscosity solvents and coatings to medium-viscosity adhesives, pharmaceutical suspensions, and food emulsions. With the optional #0 spindle, it extends sensitivity down to 1 mPa·s, making it suitable for thin oils, aqueous solutions, and dilute polymer dispersions. For temperature-sensitive applications, an optional PT100 RTD probe interfaces directly with the unit to monitor sample temperature in real time—critical for ASTM D445-compliant reporting. While the NDJ-5S itself does not carry CE or UL certification out-of-box, its modular design allows integration into GLP/GMP workflows when paired with documented calibration procedures, traceable standard oils (e.g., Cannon-Manning series), and audit-ready data logging via RS232 output.

Software & Data Management

The NDJ-5S supports ASCII-formatted data streaming via RS232 serial interface, enabling direct acquisition by third-party software (e.g., LabVIEW, Excel via terminal emulator) or dedicated thermal printers. No proprietary software is required; all output conforms to industry-standard delimiter conventions (tab or comma-separated), facilitating automated parsing, batch reporting, and LIMS integration. Timestamped measurement logs—including spindle ID, speed, viscosity, torque, and optional temperature—can be archived for 21 CFR Part 11-aligned review when combined with procedural controls (e.g., user login logs, change history documentation). Firmware updates are performed via physical reset sequence—ensuring deterministic behavior without network dependencies.

Applications

• QC release testing of industrial lubricants, transformer oils, and hydraulic fluids per ISO 3104 and ASTM D445.
• Routine monitoring of paint, ink, and coating formulations during R&D and production blending.
• Stability assessment of topical pharmaceutical gels and ointments under controlled shear profiles.
• Viscosity profiling of dairy products (e.g., yogurts, creamers) and plant-based beverages to verify texture consistency.
• Educational laboratories requiring rugged, intuitive instrumentation for teaching rheological fundamentals and Newtonian flow behavior.

FAQ

What spindle configurations are included with the NDJ-5S?

The instrument ships with four standard spindles (#1–#4), each optimized for specific viscosity ranges within the 1–100,000 mPa·s span. The #0 spindle is available separately for sub-10 mPa·s measurements.

Is temperature control integrated into the base unit?

No—temperature regulation requires external equipment. However, the NDJ-5S accepts an optional PT100 RTD probe for real-time sample temperature monitoring, and it is fully compatible with commercially available thermostatic water baths (e.g., Julabo, Thermo Scientific).

Can the NDJ-5S meet ISO/IEC 17025 calibration requirements?

Yes—when used with NIST-traceable standard oils and validated against a certified reference viscometer, the NDJ-5S supports in-house calibration programs meeting ISO/IEC 17025 clause 6.4. Full uncertainty budgets must include contributions from spindle geometry tolerance, temperature deviation, and timing resolution.

Does the instrument support continuous data logging?

It outputs real-time readings via RS232 at user-defined intervals (e.g., 1 Hz), but onboard memory is not provided. Continuous logging requires external software or a connected serial printer.

What is the warranty coverage?

Jihepu provides a 24-month limited warranty covering parts and labor for defects in materials and workmanship under normal laboratory use conditions.