YDWG SGW®-731 Automatic Digital Refractometer
| Brand | YDWG |
|---|---|
| Origin | Shanghai, China |
| Instrument Type | Benchtop Refractometer |
| Display | Full-color LCD touchscreen interface |
| Measurement Principle | Critical angle detection via high-resolution CCD array |
| Measuring Range | Refractive Index (n<sub>D</sub>): 1.30000–1.70000 |
| Brix | 0–100.00% |
| Accuracy | ±0.00001 (n<sub>D</sub>), ±0.01% (Brix) |
| Temperature Control | Built-in Peltier thermoregulation with auto-compensation (Brix-T<sub>c</sub>) |
| Sample Volume | ≥0.5 mL |
| Light Source | Long-life LED (≥100,000 h) |
| Compliance | GB/T 12143–2008, GB/T 18963–2012, GB/T 21730–2008 |
| Predefined Calibration Tables | 8 industry-specific standards (e.g., F42/F55 HFCS, glucose, sucrose, fruit/vegetable solids, honey moisture, n<sub>D20</sub>) |
| Data Storage | Internal memory + USB export + RS232/USB communication port |
| Prism Material | Sapphire-coated optical glass (chemical-resistant, scratch-resistant, easy-clean) |
Overview
The YDWG SGW®-731 Automatic Digital Refractometer is a precision benchtop instrument engineered for high-accuracy, operator-independent measurement of refractive index (nD) and soluble solids content (Brix %) across diverse liquid-phase samples. It operates on the critical angle principle: a collimated LED beam is directed onto the sample-prism interface; the resulting total internal reflection boundary is captured by a high-resolution CCD linear sensor array, enabling pixel-level determination of the critical angle with sub-microradian resolution. This optical architecture eliminates mechanical moving parts—such as rotating prisms or manual focusing mechanisms—ensuring long-term metrological stability and minimal drift. Integrated Peltier-based temperature control maintains sample temperature at 20 °C ±0.1 °C during measurement, while real-time temperature compensation (Brix-Tc) applies ISO-standard polynomial corrections to Brix values referenced to 20 °C. Designed for routine QC laboratories in food & beverage, pharmaceutical, chemical, and agricultural sectors, the SGW®-731 delivers traceable, repeatable results compliant with national standard methodologies.
Key Features
- High-resolution CCD detection system with 2048-pixel linear sensor array for precise critical angle determination
- Full-color capacitive touchscreen interface with intuitive icon-driven navigation and multilingual support (English, Chinese, Spanish)
- Auto-temperature compensation (Brix-Tc) and built-in Peltier thermostat ensuring measurement repeatability within ±0.01% Brix across ambient fluctuations
- Sapphire-enhanced optical prism: chemically inert, abrasion-resistant, and compatible with aggressive solvents (e.g., ethanol, acetone, organic acids)
- Minimal sample requirement: only 0.5 mL required per measurement; non-destructive analysis enables full sample recovery
- Internal storage for up to 1,000 measurement records with timestamp, operator ID, temperature, and calibration status metadata
- Dual data export options: direct USB flash drive transfer and RS232/USB serial communication for LIMS or ELN integration
- Preloaded calibration tables for eight regulated applications—including F42/F55 high-fructose corn syrup, glucose, sucrose, fruit juice solids, canned goods TSS, soft drink concentration, honey moisture, and nD20
Sample Compatibility & Compliance
The SGW®-731 accommodates aqueous solutions, syrups, juices, dairy filtrates, pharmaceutical elixirs, glycol-water mixtures, and low-viscosity organic liquids (η < 500 mPa·s). Its sapphire-coated prism resists corrosion from acidic (pH ≥2), alkaline (pH ≤12), and mildly oxidizing matrices. All measurement protocols align with Chinese national standards GB/T 12143–2008 (for soft drinks), GB/T 18963–2012 (for honey quality), and GB/T 21730–2008 (for fruit and vegetable juices). While not certified to ISO 21542 or ASTM D1218, its optical design and thermal management meet the performance thresholds required for GLP-compliant documentation when paired with validated SOPs and periodic verification using NIST-traceable sucrose reference standards (SRM 84d).
Software & Data Management
The embedded firmware supports audit-ready data handling: each measurement record includes date/time stamp, user login ID (configurable via 4-digit PIN), measured nD and Brix values, sample temperature, instrument serial number, and active calibration table ID. Exported CSV files contain column headers compliant with common laboratory informatics systems. USB mass-storage mode allows drag-and-drop retrieval without proprietary software. Optional PC software (YDWG RefData Manager v3.2) provides statistical trend analysis, calibration curve generation, and PDF report export with digital signature fields—fully compatible with FDA 21 CFR Part 11 requirements when deployed with Windows domain authentication and electronic signature workflows.
Applications
- Quality control of incoming raw materials (e.g., sugar syrups, fruit concentrates, honey blends)
- In-process monitoring of evaporation, blending, and pasteurization stages in beverage manufacturing
- Stability testing of pharmaceutical oral solutions and topical emulsions
- Verification of antifreeze concentration in coolant formulations (ethylene/propylene glycol–water systems)
- Research-grade characterization of polymer dissolution kinetics and solvent–polymer interactions
- Teaching laboratories for physical chemistry courses covering optical properties, solution thermodynamics, and colligative behavior
FAQ
What is the minimum sample volume required for reliable measurement?
0.5 mL is sufficient for full-coverage prism contact under standard conditions. For highly volatile or low-surface-tension samples, a 1.0 mL volume is recommended to ensure stable meniscus formation.
Does the instrument support external temperature probes or third-party water baths?
No—the SGW®-731 relies exclusively on its integrated Peltier module for thermal equilibration. External bath coupling is neither supported nor necessary due to its <±0.1 °C thermal stability specification.
Can custom calibration curves be uploaded or edited?
Yes. Users may define up to five custom calibration tables via USB import of CSV-formatted nD–concentration pairs, with linear or second-order polynomial fitting options.
Is the prism cleaning procedure compatible with ultrasonic baths?
Ultrasonic cleaning is not recommended. Use lint-free wipes moistened with deionized water or isopropanol, followed by dry nitrogen purge—per manufacturer’s maintenance protocol.
How often should verification with certified reference standards be performed?
Daily verification is advised for regulated environments; weekly verification meets general QC requirements. Certified sucrose standards (e.g., 10.00%, 30.00%, 60.00% w/w) are recommended for Brix validation.
