GW Series ASTM D1475 Standard Density Cup (Coating & Liquid Specific Gravity Tester)
| Origin | Shanghai, China |
|---|---|
| Manufacturer Type | Authorized Distributor |
| Model | GW |
| Pricing | Available Upon Request |
| Cup Volume | 37 mL @ 4 °C and 100 mL @ 4 °C |
| Calibration Reference Temperature | 4 °C |
| Balance Weight Design | Hollow brass body with precision-packed lead shot for buoyancy compensation |
Overview
The GW Series ASTM D1475 Standard Density Cup is a precision-manufactured, gravity-based liquid density measurement device engineered for rapid, operator-independent determination of specific gravity (relative density) of low-viscosity liquids—particularly coatings, varnishes, resins, solvents, oils, and thin polymer solutions. Operating on the fundamental Archimedean principle, the instrument measures the mass of a precisely defined volume of sample at a controlled reference temperature (4 °C), enabling direct calculation of density in g/mL or kg/m³. Unlike digital densitometers or oscillating U-tube analyzers, the GW cup delivers traceable, standards-compliant results without electronics, calibration fluids, or software dependencies—making it ideal for routine QC labs, production floors, and regulatory audit environments where simplicity, mechanical robustness, and ISO/IEC 17025-aligned methodology are prioritized.
Key Features
- Two standardized cup volumes: 37 mL and 100 mL, both calibrated and certified at 4 °C per ASTM D1475 and GB/T 6750–1986 specifications—ensuring full compliance with international coating industry test protocols.
- Hollow brass cup body with integrated, non-removable lead-shot counterweight system—designed to maintain neutral buoyancy when fully immersed in water at 4 °C, minimizing operator-induced error during suspension weighing.
- High-strength, corrosion-resistant brass construction with matte-finish electroplated surface—resistant to solvent exposure and repeated cleaning with acetone, xylene, or alcohol-based agents.
- Integrated hanging hook and precision-ground rim geometry—optimized for consistent immersion depth and meniscus alignment during weighing on analytical balances (0.1 mg resolution recommended).
- No moving parts, batteries, or firmware—eliminates drift, recalibration cycles, and electronic failure points; maintenance limited to periodic visual inspection and cleaning per ASTM E177 guidelines.
Sample Compatibility & Compliance
The GW Density Cup is validated for Newtonian and near-Newtonian liquids with kinematic viscosity below 500 mm²/s (cSt) at 25 °C. It is routinely employed for architectural paints, automotive basecoats, industrial primers, printing inks, lubricating oils, and cleaning solvents. The design conforms explicitly to ASTM D1475 – Standard Test Method for Density of Liquid Coatings, Inks, and Related Products, and is referenced in ISO 2811-1 (Paints and varnishes — Determination of density — Part 1: Immersion method) and GB/T 6750–1986. All units are supplied with a Certificate of Conformance indicating nominal volume tolerance (±0.2% for 37 mL; ±0.15% for 100 mL) and reference temperature traceability to NIM (National Institute of Metrology, China). Units meet GLP documentation requirements for manual density testing workflows under FDA 21 CFR Part 11–compliant laboratory quality systems when used with auditable balance records.
Software & Data Management
As a purely mechanical, analog measurement tool, the GW Density Cup requires no embedded software, drivers, or connectivity. Data acquisition is performed manually using a calibrated analytical balance and recorded in laboratory notebooks or LIMS-compatible spreadsheets. Calculation of specific gravity follows the formula: SG = (Ws − Wb) / (Ww − Wb), where Ws = weight of cup + sample, Ww = weight of cup + water (at 4 °C), and Wb = tare weight of dry cup. This manual workflow supports full audit trail integrity, satisfies ISO/IEC 17025 clause 7.7 (result reporting), and integrates seamlessly into paper-based or electronic batch records without validation overhead.
Applications
- Batch release testing of liquid coatings per ASTM D1475 and ISO 2811-1
- Raw material verification of solvents, resins, and pigments prior to formulation
- In-process density monitoring during dispersion and thinning operations
- Stability assessment of emulsions and suspensions via time-series density tracking
- Calibration verification of digital densimeters using primary-standard reference liquids (e.g., water, n-hexane, ethanol)
- Educational laboratories demonstrating fundamental density principles in materials science curricula
FAQ
What is the recommended analytical balance specification for use with the GW Density Cup?
A Class I or II analytical balance with ≥0.1 mg readability, internal calibration, and draft shield is required. Uncertainty budget must include repeatability, linearity, and buoyancy correction per ISO 9001 Annex A.3.
Can the GW cup be used for non-aqueous liquids such as toluene or methyl ethyl ketone?
Yes—provided vapor pressure and volatility are managed via sealed weighing environment and rapid handling; density values remain valid if temperature is stabilized at 4 °C prior to measurement.
Is the lead-shot counterweight serviceable or replaceable?
No—the counterweight is factory-sealed and permanently balanced; disassembly voids calibration validity and violates ASTM D1475 Section 6.2 structural requirements.
How often should the cup be recalibrated?
Volume calibration is permanent unless physically damaged; users should verify dimensional integrity annually via accredited metrology lab per ISO/IEC 17025 Clause 6.5.2.
Does the GW series comply with FDA 21 CFR Part 11 for electronic records?
While the cup itself generates no electronic data, its use within a validated manual process—including signed hard-copy worksheets and LIMS-integrated entry—fully satisfies Part 11 predicate rule requirements for density testing in pharmaceutical excipient or coating applications.
