PULUODY PLD-3535E+ Fully Automated Pour Point Tester
| Brand | PULUODY |
|---|---|
| Model | PLD-3535E+ |
| Standard Compliance | ASTM D5950-14, GB/T 3535 |
| Temperature Control Range | 50 °C to –70 °C |
| Control Accuracy | ±0.1 °C |
| Tilt Angles | 45° and 90° (motorized) |
| Temperature Interval | 2 °C, 3 °C or user-defined |
| Power Supply | AC 200 V ±10%, 50 Hz, 2000 W |
| Display | 7″ capacitive touchscreen |
| Operating Environment | 5–35 °C, <85% RH |
Overview
The PULUODY PLD-3535E+ Fully Automated Pour Point Tester is an engineered solution for precise, repeatable determination of the pour point of petroleum products—including fuel oils, heavy lubricants, base stocks, and residual fuel blends—according to internationally recognized test standards ASTM D5950-14 and GB/T 3535. The instrument implements the automated tilt method, wherein sample tubes are mechanically inclined at defined angles (45° and 90°) while cooled under precisely regulated conditions. Pour point is identified as the lowest temperature at which the sample exhibits observable movement upon tube inclination—detected via high-sensitivity optical liquid surface monitoring. Unlike manual or semi-automated systems, the PLD-3535E+ eliminates operator subjectivity by replacing visual inspection with photometric endpoint recognition, ensuring objective, traceable results across laboratories and shifts.
Key Features
- Dual independent cooling baths (2 positions), enabling concurrent comparative testing without thermal cross-talk or procedural interference
- Micro-sized cascade compression refrigeration system—air-cooled, water-free operation—delivering stable, low-noise cooling from +50 °C down to –70 °C
- Optical detection module with calibrated photodiode array for unambiguous liquid meniscus displacement sensing during tilt cycles
- High-resolution temperature control architecture achieving ±0.1 °C accuracy across the full operating range
- Programmable cooling interval (2 °C, 3 °C, or user-defined), supporting method flexibility and alignment with internal SOPs
- Integrated 7-inch capacitive touchscreen interface with intuitive navigation, real-time curve plotting, and on-device result review
- Built-in thermal printer for immediate hardcopy output of test reports including date/time stamp, sample ID, final pour point, and system diagnostics
- Modular hardware design minimizing footprint and simplifying maintenance—no external chillers, water lines, or auxiliary compressors required
Sample Compatibility & Compliance
The PLD-3535E+ is validated for use with transparent to moderately opaque petroleum liquids within ISO 3104 viscosity limits and ASTM D5950 scope boundaries. It accommodates standard pour point test tubes per ASTM D97/D5950 specifications, with dual-bath configuration supporting both routine QC screening and method validation protocols. The system meets essential requirements for GLP-compliant environments: all temperature setpoints, actual bath temperatures, tilt timing, optical signal thresholds, and endpoint decisions are digitally logged with timestamps. Audit trail functionality supports retrospective review in accordance with FDA 21 CFR Part 11 principles when paired with validated software configurations. Instrument calibration and performance verification procedures align with ISO/IEC 17025 recommendations for petroleum testing laboratories.
Software & Data Management
Control firmware operates on a dedicated microprocessor unit (MPU) with non-volatile memory for persistent parameter storage and firmware version tracking. All operational parameters—including cooling rate, tilt sequence logic, detection sensitivity, and reporting format—are configurable via the touchscreen interface. Test data (temperature vs. time, optical signal amplitude, tilt event markers) are stored locally in CSV-compatible format and exportable via USB port. Optional laptop integration enables centralized data archiving, statistical process control (SPC) charting, and integration into LIMS platforms through standardized serial or TCP/IP communication protocols. Software updates are delivered via encrypted firmware packages, maintaining integrity and version traceability.
Applications
- Quality assurance of distillate and residual fuel oils in refinery off-gas and blending operations
- Low-temperature performance evaluation of marine fuels under ISO 8217 specifications
- Base oil classification and cold flow behavior assessment in lubricant formulation labs
- Batch release testing for transformer oils and insulating fluids per IEC 60296
- Method transfer and interlaboratory comparison studies requiring high inter-operator reproducibility
- Supporting ASTM D5950-based specification development for arctic-grade diesel and aviation turbine fuels
FAQ
What standards does the PLD-3535E+ comply with?
ASTM D5950-14 and GB/T 3535 are fully implemented in hardware logic and test sequence definition.
Can the instrument operate unattended overnight?
Yes—fully automated cycle execution, endpoint detection, and report generation require no manual intervention once initiated.
Is external cooling water required?
No—the air-cooled cascade compressor eliminates dependency on chilled water infrastructure.
How is temperature uniformity verified across the two baths?
Each bath contains independent Pt100 sensors and PID-controlled cooling loops; factory calibration includes spatial mapping at three depth points per bath.
Does the system support electronic signature and audit trail for regulated environments?
Raw data logging and timestamped event records are native; full 21 CFR Part 11 compliance requires optional software validation package and networked deployment configuration.
