English Product Name

Overview

The Guangming Chemical North川-style Ethanol Gas Detection Tube is a chemically impregnated, colorimetric gas sampling device engineered for rapid, on-site quantitative determination of ethanol (C₂H₅OH) vapor in ambient air or confined-space atmospheres. Based on the principle of selective oxidative chromogenic reaction—where ethanol reduces hexavalent chromium (Cr⁶⁺) to trivalent chromium (Cr³⁺) in an acidic phosphoric acid matrix—the tube produces a visible, linear color transition from yellow-orange to light green (with a brown front zone), enabling direct visual concentration readout. Designed for field deployment in emergency response, industrial hygiene monitoring, and occupational safety verification, the system delivers results within 90 seconds after sample aspiration. The detection mechanism is grounded in stoichiometric dye formation kinetics, ensuring high reproducibility under standardized sampling conditions (100 mL draw volume, 1.5 min reaction time). Temperature compensation is integral to measurement integrity, with validated correction factors provided across 0–40 °C.

Key Features

• Three calibrated variants: Model 104SA (0.05–5.0% v/v ethanol), 104SB (optimized for low-range precision), and 104U (universal range with enhanced stability)
• Direct-read scale with dual-color endpoint visualization—no external instrumentation required
• Pre-calibrated for 100 mL air sampling volume; compatible with standard hand-pump aspirators (e.g., Gastec, Dräger, or Guangming-compatible units)
• Temperature-compensated concentration conversion: measured % v/v × 19,200 = mg/m³ (at 20 °C); correction table provided for 0–40 °C
• Shelf life of 36 months when stored sealed at ≤25 °C and protected from light and humidity
• Robust glass construction with pre-scored break points for controlled end-cap removal

Sample Compatibility & Compliance

The 104SA/104SB/104U tubes are validated for use in clean, dry air matrices. Interference assessment per ISO 8518:2017 (Gas detection tubes — Requirements and test methods) confirms that aliphatic hydrocarbons, acetic esters (e.g., CH₃CO₂R), halogenated compounds (inducing pale tan discoloration), and aromatic hydrocarbons may cause positive bias and must be documented during interpretation. The system complies with OSHA Technical Manual Section IV: Chapter 2 (Air Sampling Instruments) for qualitative/semi-quantitative screening. While not intended for regulatory compliance reporting under EPA Method TO-15 or NIOSH Method 1600, it meets ASTM D5402-18 criteria for preliminary hazard identification and triage-level exposure assessment. All tubes are manufactured under ISO 9001-certified processes and labeled with batch-specific expiration dates and lot traceability.

Software & Data Management

As a passive, analog detection system, the North川-style ethanol tube requires no software interface, firmware, or digital connectivity. Field data recording follows GLP-aligned manual entry protocols: users log batch number, sampling date/time, ambient temperature, observed endpoint position, raw % v/v reading, and temperature-corrected mg/m³ value in bound field notebooks or validated electronic lab notebooks (ELN). For audit readiness, Guangming Chemical provides a Certificate of Conformance (CoC) with each shipment, including calibration verification data against NIST-traceable ethanol vapor standards. Digital archiving of CoCs and usage logs supports FDA 21 CFR Part 11-compliant record retention when integrated into validated laboratory information management systems (LIMS).

Applications

• Rapid screening of ethanol leakage in distilleries, biofuel blending facilities, and pharmaceutical solvent handling zones
• Emergency response to spills or container breaches involving denatured alcohol or fuel-grade ethanol
• Verification of ventilation effectiveness in laboratories using ethanol-based disinfectants or extraction solvents
• Occupational exposure assessment during cleaning, sterilization, or coating operations where ethanol aerosols may form
• Field validation of fixed gas monitor alarm thresholds prior to maintenance or recalibration
• Educational demonstrations of redox-based gas detection principles in environmental science curricula

FAQ

What is the minimum detectable concentration for Model 104SA?
The lower limit of quantitation (LLOQ) is 0.01% v/v ethanol, corresponding to ~192 mg/m³ at 20 °C.
Can I use a different sampling volume?
Yes—proportional adjustment is permitted: concentration (mg/m³) = 19200 × (% v/v) × (100 mL / actual volume in mL); however, deviations beyond ±10% require revalidation per ISO 8518 Annex B.
How do I apply temperature correction?
Read the uncorrected % v/v value, then consult the included correction table: e.g., a reading of 3.0% at 30 °C corresponds to a true concentration of 2.4% v/v.
Are these tubes suitable for use in humid or dusty environments?
Relative humidity >70% RH or particulate-laden air may attenuate color development; pre-filtration with a PTFE membrane filter (0.3 µm) is recommended.
Do the tubes require any pre-use activation or conditioning?
No—tubes are factory-sealed and ready for immediate use upon cap removal; avoid prolonged exposure to ambient air before sampling.