English Product Name
| Origin | Beijing, China |
|---|---|
| Manufacturer Type | Authorized Distributor |
| Origin Category | Domestic (China) |
| Model | 3351 |
| Pricing | Upon Request |
| Density Range | 0–2 g/cm³ |
| Accuracy Class | 0.2 or 0.5 |
| Resolution | 0.0005 g/cm³ |
| Supply Voltage | 18.5–30 V DC (nominal 24 V DC) |
| Ambient Temperature | −10 to +60 °C |
| Ambient Humidity | 5–90 % RH |
| Display | Smart LCD or LED digital indicator |
| Output Signal | 4–20 mA analog with optional HART protocol |
| Mechanical Mounting | Flanged connection |
| Installation Types | Top-mount (insertion depth 850 mm) or side-mount (insertion depth 700 mm, center-to-center tap distance 500 mm, side width 150 mm) |
| Intrinsic Safety Rating | Available (per IEC 60079-11) |
| Hygienic Design Option | Available (3-A compliant, FDA-compatible wetted materials) |
Overview
The 3351 Intelligent In-Line Densimeter is a process-integrated, continuous density measurement instrument engineered for real-time monitoring of liquids and liquid-phase mixtures in industrial production environments. It operates on the fundamental hydrostatic principle: pressure generated by a fixed-height liquid column is directly proportional to the fluid’s density (P = ρgh), where P is the measured differential pressure, g is local gravitational acceleration, and h is the precisely controlled vertical distance between two pressure sensing points. By maintaining constant h and measuring ΔP with high-stability silicon-based differential pressure transduction, the device calculates density with traceable metrological integrity—eliminating sampling, offline lab analysis, or flow interruption. Designed for permanent installation in pipelines, reactors, storage tanks, and separators, it delivers stable, drift-resistant output under dynamic process conditions, including variable temperature, pressure, and suspended solids loading. Its two-wire loop-powered architecture enables seamless integration into existing DCS, PLC, and SCADA systems without additional power infrastructure.
Key Features
- Robust all-welded stainless steel construction with hermetically sealed electronics, ensuring long-term reliability in harsh chemical, thermal, and mechanical environments.
- Integrated overpressure protection (up to 4× full-scale rating) and wide operating temperature tolerance (−10 to +60 °C ambient), supporting applications involving hot crude oil, chilled glycol solutions, caustic lyes, and viscous polymer melts.
- Fixed-insertion diaphragm design with factory calibration traceable to national standards; field configuration via HART-enabled handheld communicator or PC software—no disassembly required.
- Configurable for top-mount (tank/vessel) or side-mount (pipeline) installation, with customizable insertion depths and tap spacing to accommodate site-specific geometry and flow profiles.
- Intrinsically safe (IS) variant certified per IEC 60079-11 for use in Zone 0/1 hazardous areas; hygienic version features electropolished 316L SS wetted parts, crevice-free geometry, and compliance with 3-A Sanitary Standards and FDA 21 CFR Part 11 data integrity requirements.
Sample Compatibility & Compliance
The 3351 densimeter is validated for continuous measurement across diverse liquid media—including hydrocarbons (crude oil, refined fuels, biofuels), aqueous solutions (sugar syrups, brines, alkaline cleaners), food-grade suspensions (black/green/white liquor in pulp & paper, fruit concentrates, dairy emulsions), and pharmaceutical intermediates (urea solutions, ethanol-water blends, API slurries). It tolerates moderate particulate content and non-abrasive viscosity up to 500 cP without clogging. All wetted materials meet ASTM A240/A276 316L specifications; elastomer options include EPDM, FKM, and PTFE-lined variants for aggressive chemical exposure. The instrument complies with ISO 9001 manufacturing controls, CE marking (2014/30/EU EMC Directive and 2014/68/EU PED for pressure equipment), and supports GLP/GMP audit trails when paired with compliant data acquisition software.
Software & Data Management
Configuration, diagnostics, and real-time monitoring are supported via HART 7 protocol using standard handheld communicators (e.g., Rosemount 475) or PC-based engineering tools. The embedded firmware supports linear or custom density-to-current mapping, damping adjustment (0.1–32 s), sensor health diagnostics (diaphragm strain trending, zero stability alerts), and configurable alarm thresholds. When integrated with vendor-supplied or third-party historian platforms (e.g., OSIsoft PI, Emerson DeltaV), the 4–20 mA output—optionally enhanced with digital HART variables—enables time-synchronized density logging, batch reconciliation, and SPC charting. Data export formats include CSV and OPC UA, facilitating alignment with enterprise MES and quality management systems requiring 21 CFR Part 11 electronic signature and audit trail functionality.
Applications
- Petroleum & Refining: Real-time cut-point control in distillation columns, interface detection in separator vessels, and blending ratio verification in fuel additive injection systems.
- Food & Beverage: Brix concentration tracking in juice evaporation, fat content estimation in milk standardization, and syrup density validation in carbonated beverage formulation.
- Pulp & Paper: Black liquor solids concentration monitoring pre-evaporation, green liquor causticity control, and white water consistency management.
- Chemical & Pharma: Reaction mixture density profiling for stoichiometric endpoint detection, solvent recovery efficiency assessment, and final product density verification per USP or EP 2.2.10 specifications.
- Mining & Hydrometallurgy: Slurry density control in leaching circuits and tailings management systems.
FAQ
What is the recommended installation orientation?
Vertical installation—perpendicular to the local horizontal plane—is mandatory to ensure hydrostatic column height (h) remains geometrically invariant; angular deviation >±2° introduces systematic bias exceeding ±0.001 g/cm³.
Can the device measure density in flowing versus static media?
Yes. The 3351 is validated for both dynamic pipeline flow (Re > 2,000) and quiescent tank conditions; flow-induced vibration is mitigated by internal damping and rigid mechanical mounting.
How is local gravity compensated during calibration?
During commissioning, the user inputs either the precise latitude/altitude or measured g-value (m/s²); the firmware applies this correction factor to convert raw ΔP into absolute density referenced to SI units.
Is recalibration required after field installation?
No routine recalibration is needed if mechanical integrity is maintained; however, annual verification against NIST-traceable density standards (e.g., certified glycerol/water mixtures) is recommended for GxP-regulated environments.
What documentation accompanies the instrument?
Each unit ships with a Factory Calibration Certificate (including as-found/as-left data), EC Declaration of Conformity, Installation & Operation Manual, and Quality Assurance Certificate compliant with ISO 17025-accredited calibration practices.
