Sanpu GL-102B Electronic Soap Film Flowmeter

Overview

The Sanpu GL-102B Electronic Soap Film Flowmeter is a precision gravimetric flow measurement instrument engineered for direct, real-time quantification of low-to-moderate gas or liquid flow rates in laboratory, calibration, and quality control environments. It operates on the well-established soap film displacement principle: a thin, stable soap film is formed across the calibrated glass tube cross-section; as fluid passes through, the film traverses a known distance between two optical sensors. The transit time is measured with microsecond-level internal timing resolution (0.01 s), and volumetric flow is calculated using the fixed tube geometry. Integrated temperature and pressure sensors enable automatic compensation per ISO 6145-1 and ASTM D5400, allowing concurrent derivation of both volumetric flow (mL/min at actual conditions) and standardized mass flow (e.g., mL/min at STP or NTP). Unlike thermal or differential pressure meters, the GL-102B provides traceable, primary-standard-level accuracy without requiring upstream/downstream straight-pipe runs or fluid property assumptions—making it ideal for calibrating mass flow controllers (MFCs), validating gas chromatography carrier gas flows, and verifying environmental air sampling pumps.

Key Features

• High-precision optical detection system with dual infrared sensors for consistent soap film edge recognition and minimal operator dependency.
• Integrated environmental monitoring: onboard Pt100 temperature sensor (±0.2 °C) and piezoresistive pressure transducer (±0.5 kPa) for real-time compensation.
• Large backlit LCD display showing simultaneous readings of elapsed time, measured volume, ambient temperature, barometric pressure, uncorrected flow, and compensated volumetric/mass flow.
• Three-button interface enabling rapid zeroing, start/stop triggering, and statistical processing—including five-point averaging with min/max deviation reporting per ISO/IEC 17025 data integrity guidelines.
• Dual-power architecture: long-life rechargeable Ni-MH battery (4.8 V / 700 mAh) supporting >300 hours of standby operation, plus field-replaceable 9 V DC input that powers the unit and recharges the battery simultaneously via regulated charging circuitry.
• Calibration-ready design: includes built-in reference volume verification function and user-accessible calibration constants for traceable field adjustment against NIST-traceable standards.

Sample Compatibility & Compliance

The GL-102B is compatible with non-corrosive, non-particulate gases (e.g., N₂, O₂, air, He, CO₂) and low-viscosity liquids (e.g., water, ethanol, IPA) within its specified 1–1000 mL/min range. Its borosilicate glass measurement tube ensures chemical inertness and optical clarity. The instrument complies with fundamental metrological requirements outlined in ISO/IEC 17025:2017 (clause 6.5 on equipment verification), supports GLP/GMP audit readiness through timestamped measurement logs, and meets general electrical safety standards per IEC 61010-1 for laboratory equipment. While not FDA 21 CFR Part 11–certified out-of-the-box, its deterministic measurement logic and immutable local data storage (no cloud upload) facilitate validation under regulated QC workflows when paired with documented SOPs.

Software & Data Management

The GL-102B operates as a standalone, embedded-system device with no proprietary software dependency. All measurements are stored locally in non-volatile memory with timestamps, sensor readings, and calculation parameters. Data export is performed manually via visual transcription or optional RS-232 serial interface (available upon request) for integration into LIMS or custom Python/Matlab acquisition scripts. No firmware updates are required during normal operation; calibration coefficients remain persistent across power cycles. For laboratories requiring electronic records, the unit’s deterministic output format (ASCII text with fixed-field delimiters) enables straightforward parsing and archiving compliant with ALCOA+ principles (Attributable, Legible, Contemporaneous, Original, Accurate, Complete, Consistent, Enduring, Available).

Applications

• Calibration and verification of gas chromatography carrier gas flow rates (e.g., split/splitless inlet, detector make-up gas).
• Validation of low-flow air samplers used in occupational hygiene (NIOSH Method 0500) and ambient air monitoring (EPA TO-15, Method 18).
• Performance testing of mass flow controllers (MFCs) and rotameters prior to installation in analytical or process systems.
• Flow characterization of microfluidic devices, permeation cells, and membrane diffusion studies.
• Education and training in fluid mechanics labs where visual, principle-based flow measurement reinforces theoretical concepts.

FAQ

What is the measurement uncertainty of the GL-102B under standard conditions?

The stated accuracy is ±1% of reading, derived from combined contributions of timing resolution (±0.01 s), tube geometry tolerance (±0.3%), and sensor uncertainties (temperature ±0.2 °C, pressure ±0.5 kPa), validated per ISO 5167 Annex C methodology.

Can the GL-102B measure corrosive or humid gases?

No. The soap film method requires non-reactive, low-humidity gases to maintain film stability. For HCl, Cl₂, NH₃, or saturated streams, alternative techniques such as laminar flow elements or ultrasonic meters are recommended.

Is factory calibration certificate included?

Yes—each unit ships with a manufacturer-issued calibration report referencing traceable standards (NIST SRM 2800 series for volume, Fluke 720A for pressure, and PT100 reference thermometer), valid for 12 months from date of shipment.

How often should field recalibration be performed?

Per ISO/IEC 17025, recalibration is recommended annually or after any physical impact, sensor replacement, or observed drift exceeding ±0.5% of full scale during routine verification checks.

Does the GL-102B support multi-point flow profiling?

No—it measures instantaneous single-point flow only. For velocity profile analysis, pairing with a traverse mechanism and external data logger is required.