HUANKONG GHK-7000Z Digital Soap Film Flowmeter

Overview

The HUANKONG GHK-7000Z Digital Soap Film Flowmeter is a precision volumetric flow calibration instrument engineered for traceable, low-flow gas measurement in laboratory and field-deployed environmental monitoring applications. It operates on the well-established soap film method—a gravimetrically traceable primary standard technique defined in JJG 586–2006 and widely accepted under ISO/IEC 17025-accredited calibration frameworks. Unlike thermal or differential pressure-based flowmeters, the GHK-7000Z directly measures elapsed time for a soap film to traverse a known internal tube volume, eliminating reliance on fluid property assumptions or sensor drift compensation. This principle delivers high reproducibility (±0.5% full-scale typical) across its three selectable flow ranges—optimized for calibrating air samplers, respirable dust cyclones, bioaerosol impactors, flue gas analyzers, and GC carrier gas lines operating between 10 mL/min and 30 L/min. Its modular architecture allows rapid interchange of calibrated soap film detection cartridges, enabling metrological flexibility without recalibration downtime.

Key Features

• Modular detector system with factory-calibrated, interchangeable soap film tubes—each certified per JJG 586–2006 with individual traceability documentation
• High-resolution infrared photogate array with microsecond-level timing accuracy (time resolution: 0.001 s) and automatic film-edge detection logic
• 4.3-inch capacitive color touchscreen interface supporting multilingual UI (English default), intuitive menu navigation, and real-time parameter visualization
• Integrated environmental compensation engine applying real-time temperature and barometric pressure inputs to convert measured volume to STP (273.15 K, 101.325 kPa) or NTP (293.15 K, 101.325 kPa) conditions
• Opaque acrylic tube housing with UV-stabilized polymer construction—minimizes ambient light interference and ensures consistent film formation under variable lighting conditions
• Dual power operation: AC mains input (100–240 VAC, 50/60 Hz) and internal rechargeable lithium-ion battery (≥8 h continuous use, status-indicated via on-screen battery icon)
• USB Type-B port for direct data export to PC; supports FAT32-formatted USB flash drives for batch storage of calibration records (CSV format)

Sample Compatibility & Compliance

The GHK-7000Z is validated for use with non-corrosive, non-condensing gases including ambient air, nitrogen, helium, and synthetic air—commonly employed in occupational hygiene sampling, EPA Method-compliant stack testing, and ISO 14644 cleanroom airflow verification. It meets the metrological requirements of JJG 586–2006 for verification of volumetric flow standards used in accredited laboratories. While not intrinsically rated for hazardous areas, its design conforms to IEC 61010-1 safety standards for electrical equipment used in measurement, control, and laboratory applications. The device supports GLP-aligned workflows through timestamped, operator-annotated calibration logs and optional Bluetooth thermal printing for hard-copy audit trails—facilitating compliance with ISO/IEC 17025 clause 7.7 (result reporting) and USP analytical instrument qualification protocols.

Software & Data Management

No proprietary software installation is required. All data—including raw transit time, calculated volumetric flow (in mL/min), compensated STP/NTP values, ambient T/P readings, and user-entered identifiers—are stored internally and exported as plain-text CSV files via USB. Each record contains ISO 8601 timestamps, instrument serial number, detector ID, and correction coefficients applied. Optional Bluetooth-enabled thermal printers generate tamper-evident paper reports with embedded calibration certificate headers—suitable for inclusion in QA documentation packages. Firmware updates are delivered via USB drive and include version-controlled changelogs compliant with ICH Q9 risk management principles.

Applications

• Periodic verification of low-flow rate performance in personal air sampling pumps (OSHA ID-130, NIOSH 0500/0600)
• Calibration of microbial cascade impactors and liquid impingers per ISO 14698-1 biological contamination control guidelines
• Field validation of portable VOC monitors and PID-based gas detectors prior to deployment
• Flow rate auditing of GC carrier gas systems to ensure retention time stability and method reproducibility
• Supporting ISO 50001 energy management audits by quantifying compressed air leakage rates at point-of-use
• Academic research requiring traceable gas flow references for reaction stoichiometry or mass transfer coefficient determination

FAQ

Is the GHK-7000Z suitable for calibrating high-flow industrial gas meters?
No—it is optimized for low-to-medium flow ranges up to 30 L/min and is not designed for custody-transfer or pipeline-level metering applications.
Does the unit require annual recalibration?
Yes; per JJG 586–2006, verification intervals shall not exceed 12 months when used in legally mandated or quality-critical environments. Certificate of calibration includes uncertainty budget per GUM (JCGM 100:2008).
Can the soap film tubes be cleaned and reused?
Yes—tubes are chemically resistant to standard laboratory detergents and isopropyl alcohol; however, repeated cleaning may affect surface wettability over time, necessitating periodic replacement per manufacturer’s service bulletin.
Is firmware upgrade capability available post-purchase?
Yes—firmware updates are provided free of charge via HUANKONG’s authorized distributor portal and include enhanced data logging features and expanded language support.
What environmental conditions affect measurement accuracy?
Ambient temperature gradients exceeding ±2 °C/min or barometric pressure fluctuations >0.1 kPa/min may introduce transient errors; the built-in compensation algorithms assume stable conditions during each measurement cycle (typically <10 s duration).