Hengping NDJ-5S Digital Display Rotational Viscometer
| Brand | Hengping |
|---|---|
| Origin | Shanghai, China |
| Model | NDJ-5S |
| Instrument Type | Rotational Viscometer |
| Viscosity Range | 1–1×10⁵ mPa·s |
| Rotors | Standard #1–#4, Optional #0 (0.1–10 mPa·s) |
| Rotational Speeds | 6, 12, 30, 60 rpm |
| Accuracy | ±2% (for Newtonian liquids) |
| Display | Backlit LCD with bilingual (Chinese/English) UI |
| Interface | RS-232 serial port |
| Power Supply | AC 220 V ±10%, 50 Hz ±10% |
| Operating Environment | 5–35 °C, ≤80% RH |
| Dimensions | 380 × 320 × 390 mm |
| Net Weight | 4.5 kg |
Overview
The Hengping NDJ-5S Digital Display Rotational Viscometer is a precision-engineered instrument designed for routine and quality control viscosity measurements of both Newtonian and non-Newtonian fluids. Based on the Couette principle, it employs a motor-driven spindle rotating at precisely controlled speeds within a stationary sample cup or cylinder. The resulting torque exerted by the fluid on the rotating spindle is measured via a calibrated sensor and converted into dynamic viscosity (mPa·s) using microprocessor-based signal processing. Unlike capillary or falling-ball viscometers, rotational systems provide direct, real-time shear stress–shear rate relationship capability—enabling reliable determination of apparent viscosity across defined shear conditions. The NDJ-5S operates at four discrete rotational speeds (6, 12, 30, and 60 rpm), each paired with one of four standard spindles (#1–#4), delivering a total measurable range from 1 to 100,000 mPa·s. An optional #0 spindle extends low-viscosity coverage down to 0.1 mPa·s, supporting applications in solvents, thin coatings, and pharmaceutical dispersions.
Key Features
- Microprocessor-controlled rotational speed and spindle selection with automatic range optimization logic
- High-contrast, blue-backlit LCD display supporting dual-language (English/Chinese) interface for international laboratory use
- All-aluminum housing with electromagnetic shielding for stable operation in electrically noisy environments
- Integrated RS-232 serial interface compliant with EIA/TIA-232 standards for direct connection to PCs or data loggers
- Modular design enabling field-installation of optional accessories: PT100 temperature probe (for real-time sample temperature monitoring), thermal printer module (for hard-copy output), and extended-range spindle sets
- Self-calibrating torque sensing system with digital filtering to minimize drift and improve repeatability
- Stable mechanical architecture ensuring long-term calibration retention under continuous QC usage
Sample Compatibility & Compliance
The NDJ-5S accommodates a broad spectrum of industrial and research samples—including edible oils, polymer melts, paint formulations, cosmetic emulsions, food suspensions, detergent solutions, and pharmaceutical syrups. Its spindle geometry conforms to ASTM D2196 and ISO 2555 guidelines for rotational viscosity measurement of non-Newtonian materials. While not certified for GLP or GMP-regulated environments out-of-the-box, the instrument supports audit-ready data export when used with validated third-party software that implements 21 CFR Part 11-compliant electronic signatures and audit trails. Temperature compensation functionality—when paired with an external PT100 probe—is traceable to NIST-traceable reference standards. All electrical components meet CE marking requirements per EN 61010-1 for laboratory equipment safety.
Software & Data Management
The NDJ-5S ships with proprietary Windows-compatible acquisition software distributed on CD-ROM. This application enables time-stamped data logging, customizable report generation (PDF/CSV), multi-curve overlay analysis, and batch export of viscosity vs. shear rate profiles. Raw torque and RPM values are transmitted in ASCII format over RS-232 at 9600 baud, allowing integration with LabVIEW, MATLAB, or LIMS platforms via custom scripting. Firmware updates are delivered via serial upload and preserve user-defined calibration offsets. Data integrity is reinforced through cyclic redundancy check (CRC) validation during transmission. No cloud connectivity or remote access features are implemented—ensuring full data sovereignty for regulated users.
Applications
- Quality assurance of lubricants and transformer oils per ASTM D445
- Routine viscosity checks in paint and ink manufacturing per ISO 2555
- Batch release testing of oral suspensions and topical gels in pharmaceutical production
- Process monitoring of starch pastes, dairy concentrates, and fruit purees in food R&D
- Evaluation of thixotropic recovery behavior using sequential speed ramp protocols
- Viscosity grading of silicone fluids and adhesives in elastomer formulation labs
FAQ
What spindle configurations are supported by the NDJ-5S?
Standard delivery includes spindles #1 through #4. Optional #0 spindle is available for measuring ultra-low-viscosity fluids (0.1–10 mPa·s).
Is temperature control integrated into the base unit?
No—temperature measurement requires optional PT100 probe connected via dedicated analog input; active temperature regulation (e.g., Peltier bath) must be provided externally.
Can the NDJ-5S comply with FDA 21 CFR Part 11 requirements?
The hardware itself does not include electronic signature or audit trail capabilities; compliance depends on the configuration and validation of the host PC software and procedural controls.
What is the recommended recalibration interval?
Annual verification against traceable standard oils (e.g., Cannon-Manning series) is advised for QC-critical applications; more frequent checks may be required per internal SOPs.
Does the instrument support continuous rotation mode or only discrete speed steps?
It operates exclusively at the four fixed speeds: 6, 12, 30, and 60 rpm—no variable-speed or ramping capability is implemented in firmware.
