Jihepu WRS-1B Digital Melting Point Apparatus
| Brand | Jihepu |
|---|---|
| Origin | Shandong, China |
| Model | WRS-1B |
| Temperature Range | 30–300 °C |
| Programmable Heating Rates | 0.2, 0.5, 1.0, 1.5, 2.0, 3.0, 4.0, 5.0 °C/min |
| Temperature Resolution | ±0.4 °C (≤200 °C), ±0.7 °C (200–300 °C) |
| Repeatability | ≤0.3 °C at 1.0 °C/min |
| Capillary Dimensions | OD 1.4 mm, ID 1.0 mm |
| Sample Capacity | 3 capillaries simultaneously |
| Power Supply | 220 V ±10%, 50 Hz, 100 W |
| Dimensions (W×D×H) | 398 × 278 × 210 mm |
| Net Weight | 12.5 kg |
Overview
The Jihepu WRS-1B Digital Melting Point Apparatus is a precision thermal analysis instrument engineered for accurate, reproducible determination of solid-phase transition temperatures in organic and pharmaceutical compounds. It operates on the principle of controlled linear heating combined with real-time optical detection of sample opacity changes during melting—a method standardized under ASTM E324 and ISO 6382 for routine purity assessment and identity verification. Designed for laboratory environments requiring compliance with GLP and basic GMP documentation practices, the WRS-1B delivers traceable temperature control across a 30–300 °C range, supporting both manual observation and automated data capture via RS232 interface. Its dual-function display shows both current temperature and real-time derivative-like visual feedback of melt onset and completion, enabling unambiguous identification of onset, clear point, and endset temperatures per ICH Q5C and USP <741> guidelines.
Key Features
- Eight selectable linear heating rates (0.2–5.0 °C/min), each calibrated to within ±10% of setpoint—critical for method development and inter-laboratory comparability.
- Digital photometric detection system with high-contrast LED illumination and integrated photodiode sensor, eliminating subjective visual interpretation errors common in analog units.
- Simultaneous triple-capillary measurement capability (standard 1.4 mm OD / 1.0 mm ID glass capillaries), allowing parallel analysis of reference, test, and duplicate samples for statistical validation.
- Temperature resolution of ±0.4 °C below 200 °C and ±0.7 °C up to 300 °C, verified against NIST-traceable reference standards (e.g., indium, tin, lead).
- Onboard memory stores up to 100 measurement records with timestamp, heating rate, and final melt interval—exportable as CSV via serial connection for LIMS integration.
- Rugged aluminum alloy housing with passive thermal shielding ensures stable ambient drift compensation and mechanical durability in shared QC lab settings.
Sample Compatibility & Compliance
The WRS-1B accommodates standard 100 mm-length capillaries filled to ≥3 mm height with dry, finely powdered crystalline samples—compatible with APIs, excipients, polymers, and small-molecule intermediates. Its design conforms to the physical geometry and thermal response expectations defined in pharmacopoeial monographs (USP <741>, EP 2.2.17, JP 2.60). While not FDA 21 CFR Part 11–validated out-of-the-box, the instrument supports audit-ready operation when paired with validated PC software and documented SOPs—including electronic signature protocols, change control logs, and raw data archiving. Temperature calibration certificates are provided with each unit, referencing certified reference materials traceable to national metrology institutes.
Software & Data Management
Data acquisition is supported through an industry-standard RS232 serial interface (DB9 connector), enabling bidirectional communication with Windows-based host applications. The included utility software permits real-time graphing of temperature vs. time curves, automatic onset/endset detection using first-derivative thresholding, and export of ASCII/CSV files compatible with Excel, MATLAB, or LabWare LIMS. All exported datasets retain full metadata: operator ID, date/time stamp, heating rate, capillary position, and user-defined sample ID. For regulated environments, the system architecture allows integration into 21 CFR Part 11–compliant workflows when deployed with validated third-party data management platforms that enforce electronic signatures, audit trails, and role-based access control.
Applications
- Pharmaceutical quality control: Identity testing and purity estimation of active pharmaceutical ingredients (APIs) per USP general chapter <741>.
- Chemical synthesis validation: Confirmation of product crystallinity and batch-to-batch consistency in fine chemical manufacturing.
- Academic research: Teaching fundamental thermal behavior concepts in undergraduate chemistry labs and graduate-level materials science courses.
- Food & cosmetics R&D: Monitoring phase transitions in waxes, emulsifiers, and lipid-based formulations.
- Regulatory submission support: Generating repeatable, defensible melting data for ANDA, DMF, and CMC sections of regulatory dossiers.
FAQ
What capillary dimensions are required for optimal performance?
Standard capillaries with outer diameter 1.4 mm and inner diameter 1.0 mm are specified; deviations may affect heat transfer uniformity and observed melt intervals.
Is the instrument suitable for measuring decomposition-onset temperatures?
No—the WRS-1B is optimized for sharp, reversible solid–liquid transitions; it does not provide dynamic gas atmosphere control or evolved gas analysis needed for decomposition studies.
Can the heating rate be modified during an ongoing measurement?
No—rate selection is fixed prior to initiation; this ensures thermal equilibrium compliance per ISO 6382 Annex A requirements.
Does the device meet GLP documentation requirements?
Yes, when operated with validated procedures, calibrated reference standards, and complete record retention—including raw photometric output and environmental logs.
What maintenance is required to sustain accuracy over time?
Annual recalibration against certified reference substances (e.g., caffeine, acetanilide, urea) is recommended; optical path cleaning every 6 months prevents signal attenuation from dust accumulation.
