YDWG WRS-1B Digital Melting Point Apparatus
| Brand | YDWG |
|---|---|
| Origin | Shanghai, China |
| Model | WRS-1B |
| Temperature Range | Ambient to 320 °C |
| Heating Rates | 0.2, 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, 5.0 °C/min (8 selectable steps) |
| Temperature Repeatability | ±0.3 °C at 1.0 °C/min |
| Temperature Accuracy | ±0.4 °C ≤200 °C |
| Temperature Resolution | 0.1 °C |
| Capillary Dimensions | OD 1.4 mm, ID 1.0 mm, Length 90 mm |
| Sample Capacity | 1 capillary per run |
| Display | 5.6-inch color LCD |
| Calibration | Multi-point calibration support |
| Interface | RS232 and USB |
| Power | 220 V ±10%, 50 Hz, 80 W |
| Dimensions | 360 × 290 × 170 mm |
| Net Weight | 9 kg |
Overview
The YDWG WRS-1B Digital Melting Point Apparatus is a precision thermal analysis instrument engineered for reliable, reproducible determination of melting point intervals in solid organic compounds, pharmaceuticals, polymers, and reference standards. It operates on the principle of optical detection of phase transition—specifically, the onset and completion of solid-to-liquid transformation—as observed through a calibrated capillary tube under controlled linear heating. The system employs a high-linearity platinum resistance thermometer (Pt100) as its primary temperature sensor, coupled with PID-based closed-loop temperature control to ensure stable ramp profiles across its full operating range (ambient to 320 °C). Designed in strict alignment with pharmacopoeial requirements—including USP <741>, EP 2.2.17, and ChP IV—this apparatus uses standardized 1.0 mm inner diameter capillaries (90 mm length, 1.4 mm outer diameter), enabling direct comparability with regulatory reference methods.
Key Features
- Precision temperature control with eight discrete, user-selectable heating rates (0.2–5.0 °C/min), each programmable with ±10% linearity tolerance per pharmacopoeial specification
- Optical detection module with real-time photodiode-based monitoring of sample opacity changes during melting, eliminating subjective visual interpretation
- High-resolution 5.6-inch color LCD interface supporting intuitive numeric keypad input, on-screen parameter configuration, and simultaneous display of initial melt (onset), final melt (clear point), and dynamic temperature curve
- Multi-point calibration capability compliant with ISO/IEC 17025 traceability requirements, supporting verification at ≥3 reference temperatures (e.g., 90 °C, 150 °C, 220 °C)
- Robust mechanical design with thermally isolated sample chamber and low-thermal-mass heating block, minimizing thermal lag and improving inter-run consistency
- Integrated data export via RS232 and USB interfaces for seamless integration into laboratory information management systems (LIMS) or electronic lab notebooks (ELN)
Sample Compatibility & Compliance
The WRS-1B accepts single standard pharmaceutical-grade capillaries (1.0 mm ID, 1.4 mm OD, 90 mm length) filled with 2–3 mm of dry, finely powdered sample—ensuring uniform heat transfer and minimizing superheating artifacts. Its measurement protocol conforms to internationally recognized standards for melting point determination, including ASTM E324 (Standard Test Method for Linear Thermal Expansion of Solid Materials), USP <741> (Melting Points and Distillation Ranges), and Chinese Pharmacopoeia (ChP) Volume IV. The instrument supports GLP-compliant operation through audit-trail-capable data logging (when paired with compatible software) and meets essential electrical safety requirements per IEC 61010-1 for laboratory equipment.
Software & Data Management
While the WRS-1B operates as a standalone instrument with embedded firmware, its RS232 and USB ports enable bidirectional communication with external PCs running validated thermal analysis software. Exported datasets include timestamped temperature readings, detected onset/clear points, heating rate metadata, and operator ID fields—facilitating 21 CFR Part 11–compliant record retention when used with appropriate software validation packages. Optional thermal printers (e.g., RD-TH32-SC) provide hard-copy output of results with instrument ID, date/time stamp, and calibration status indicators. All firmware updates and configuration backups are performed via USB mass-storage mode without requiring proprietary drivers.
Applications
- Quality control testing of active pharmaceutical ingredients (APIs) and excipients per ICH Q5 and Q6 guidelines
- Identity verification and purity assessment of synthetic intermediates and fine chemicals
- Stability-indicating method development for accelerated degradation studies
- Educational use in university chemistry and pharmacy laboratories for teaching phase transition thermodynamics
- Reference standard qualification in metrology labs supporting ISO/IEC 17034-certified material producers
- Regulatory submission support for ANDA, NDA, and DMF dossiers requiring documented melting behavior
FAQ
Does the WRS-1B support automatic averaging across multiple runs?
Yes—the instrument stores up to 10 sequential measurements and calculates mean onset, mean clear point, and standard deviation automatically upon completion of a defined batch sequence.
Is multi-capillary measurement possible on this model?
No—the WRS-1B is configured for single-capillary analysis per test cycle. For parallel throughput, users should consider the WRS-2 series or third-party automated feeders compatible with YDWG’s communication protocol.
What calibration standards are recommended for routine verification?
Certified reference materials such as pure caffeine (mp 235–236 °C), indomethacin (mp 156–157 °C), and urea (mp 132–133 °C) are routinely used; calibration points must span the intended operational range and be traceable to NIST or equivalent national metrology institutes.
Can the instrument be integrated into a networked LIMS environment?
Yes—via ASCII-based serial protocol over RS232 or virtual COM port over USB, enabling structured data ingestion into validated LIMS platforms with configurable field mapping and digital signature workflows.
