KEM DAP On-line Automatic Digital Density Meter

Overview

The KEM DAP On-line Automatic Digital Density Meter is an industrial-grade, process-integrated density measurement system engineered for continuous, unattended operation in chemical, pharmaceutical, food & beverage, and petrochemical production environments. It integrates KEM’s proven portable digital density meter DA-130N into a robust, IP-rated enclosure with automated fluid handling modules—enabling fully autonomous sampling, measurement, cell rinsing, temperature equilibration, and periodic calibration verification. The instrument operates on the oscillating U-tube principle (ASTM D4052, ISO 12185), where the resonant frequency of a precisely machined glass U-tube filled with sample correlates directly to its density with high reproducibility and minimal sample volume requirement (~1 mL per cycle). Designed for 24/7 deployment in controlled ambient conditions (0–40 °C), the DAP delivers traceable, temperature-compensated density data synchronized with real-time process monitoring systems.

Key Features

• Fully automated operational cycle: programmable sequence of sample aspiration, density measurement, integrated solvent rinse (e.g., deionized water or ethanol), air purge, and optional reference standard verification.
• High-precision oscillating U-tube sensor with temperature-controlled Peltier element ensuring thermal stability within ±0.01 °C during measurement.
• Density resolution of 0.0001 g/cm³ and accuracy of ±0.001 g/cm³ across the full range (0.0000–2.0000 g/cm³), validated per ISO/IEC 17025-accredited procedures.
• Multi-parameter output: simultaneous calculation and display of density, temperature-corrected density, specific gravity (relative density), Brix (% w/w), alcohol content (% v/v), sulfuric acid concentration (% w/w), API gravity, Baumé degree, and Plato scale—using user-configurable, NIST-traceable conversion algorithms.
• Flexible communication interface: RS-232C and USB 2.0 ports support direct connection to SCADA, DCS, or LIMS; ASCII-based protocol enables seamless integration with LabVIEW, MATLAB, or custom OPC UA clients.
• Modular mechanical design: compact footprint (approx. 300 × 300 × 300 mm) with front-access service panel, quick-release fluid path fittings, and chemically resistant wetted materials (borosilicate glass, PTFE, 316 stainless steel).

Sample Compatibility & Compliance

The DAP is compatible with homogeneous liquids, low-viscosity suspensions (< 500 mPa·s), and clear solutions—including aqueous electrolytes, organic solvents, syrups, fermentation broths, and hydrocarbon blends. It is not intended for slurries, highly viscous polymers, or corrosive media exceeding pH 2–12 without optional material upgrades. The system complies with CE marking requirements (2014/30/EU EMC Directive, 2014/35/EU LVD), meets IEC 61000-6-2/6-4 immunity/emission standards, and supports audit-ready documentation per FDA 21 CFR Part 11 when paired with compliant data acquisition software. Optional IQ/OQ documentation packages are available for GMP/GLP-regulated installations.

Software & Data Management

The DAP operates standalone with embedded firmware supporting configurable measurement intervals (1–3600 seconds), alarm thresholds (e.g., density drift > ±0.002 g/cm³), and automatic log generation. Raw and processed data—including timestamps, temperature, and operator ID—are stored internally (≥10,000 records) and exportable via USB mass storage mode. KEM’s optional DAS-DAQ software provides real-time graphing, statistical trend analysis (X-bar/R charts), PDF report generation, and electronic signature capability aligned with ALCOA+ data integrity principles. All data transfers retain full metadata: measurement uncertainty, calibration history, and environmental conditions.

Applications

• Continuous concentration control in sugar refining (Brix monitoring), ethanol distillation, and acid dosing processes.
• In-line quality verification of API synthesis intermediates and final drug substance batches per USP and Ph. Eur. 2.2.39.
• Real-time density feedback for blending optimization in lubricant formulation and fuel additive manufacturing.
• Wastewater treatment plant inflow characterization and dissolved solids estimation.
• Validation of cleaning-in-place (CIP) endpoint via conductivity-density correlation during equipment sanitization cycles.

FAQ

What sample volume is required per measurement cycle?

Approximately 1.0–1.2 mL of liquid is drawn per analysis; total system hold-up volume is < 5 mL.
Can the DAP be installed in hazardous areas?

Standard units are rated for non-hazardous locations (Class I, Division 2 not certified); ATEX/IECEx variants require factory configuration and separate quotation.
Is temperature control internal or external?

The DAP features an integrated Peltier-based thermostat with PID control; no external chiller is needed for operation within 0–40 °C ambient.
How often does the system require recalibration?

KEM recommends daily verification with certified reference standards (e.g., air/water); full recalibration every 3–6 months depending on usage intensity and regulatory requirements.
Does the DAP support MODBUS RTU or TCP/IP protocols?

Native MODBUS RTU over RS-485 is available as a factory-installed option; TCP/IP requires third-party gateway integration.