NorthKawamura NMHC Quick-Test Colorimetric Gas Detection Tube 187S

Overview

The NorthKawamura NMHC Quick-Test Colorimetric Gas Detection Tube 187S is a field-deployable, chemical reaction–based analytical tool engineered for the rapid, semi-quantitative determination of non-methane hydrocarbons (NMHC) in ambient or workplace air. Operating on the principle of colorimetric gas detection, the tube contains a solid-phase reagent bed impregnated with oxidizing agents and chromogenic compounds specifically formulated to react stoichiometrically with unsaturated and saturated non-methane volatile organic compounds (VOCs). When sampled air is drawn through the tube using the AP-20 hand pump, NMHC molecules undergo oxidation, generating a localized color front whose length is directly proportional to concentration. The measurement relies on diffusion-controlled reaction kinetics and calibrated stain progression under standardized flow and temperature conditions—enabling direct visual readout without instrumentation, power supply, or ignition sources.

Key Features

• Single-use, disposable glass tube with pre-calibrated linear scale (mm), optimized for NMHC detection in the designated range (typical span: 5–500 ppm C₃H₈ equivalent, per manufacturer’s calibration protocol)
• Compatible exclusively with the AP-20 dual-stroke hand pump (certified flow rate: 100 mL ± 5% per stroke; total sampling volume: 100 mL or 200 mL depending on tube configuration)
• No electrical components, batteries, or consumables beyond the tube and pump—ideal for Zone 0/1 hazardous locations where intrinsic safety is mandatory
• Measurement completed within ≤ 90 seconds post-sampling; no sample storage, transport, or laboratory analysis required
• Stable shelf life of ≥ 24 months when stored at 5–30 °C in original sealed packaging; lot-specific calibration certificates provided with each batch
• Robust borosilicate glass construction with laser-etched graduation marks and inert internal coating to prevent reagent migration or wall adsorption artifacts

Sample Compatibility & Compliance

The 187S tube is validated for use with ambient air, stack effluent dilutions, and indoor workplace atmospheres containing aliphatic and aromatic NMHC species (e.g., propane, butane, toluene, xylene), excluding methane and carbon monoxide. Cross-sensitivity to H₂S, SO₂, and Cl₂ is documented and listed in the technical datasheet; users are advised to consult interference tables prior to deployment. While not a regulatory compliance instrument per se, the method aligns with ISO 8573-1 Annex B (for qualitative screening), JIS K 0121 (Japanese Industrial Standard for gas detector tubes), and OSHA Technical Manual Section II: Chapter 2 (field screening protocols). Data generated may serve as preliminary evidence supporting subsequent GC-FID or GC-MS quantification in GLP-compliant environmental monitoring programs.

Software & Data Management

This analog detection system requires no software, firmware, or digital interface. All measurement data are captured manually via direct visual observation and recorded in field logbooks or electronic lab notebooks (ELNs). For traceability, users must document tube lot number, AP-20 pump calibration status, sampling date/time, temperature, humidity, and observer initials. When integrated into enterprise EHS management platforms (e.g., Intelex, Sphera), manual entries can be tagged with GPS coordinates and photo documentation of the color front—supporting audit readiness under ISO 14001 and OHSAS 18001 frameworks. No FDA 21 CFR Part 11 requirements apply due to absence of electronic records generation.

Applications

• Rapid leak detection during refinery maintenance, petrochemical plant turnaround, or LNG terminal inspections
• Workplace exposure assessment for NMHC near solvent-handling stations, paint booths, or adhesive application zones
• Emergency response triage following VOC spills or vapor cloud incidents—providing immediate hazard classification (TLV-TWA vs. STEL thresholds)
• Pre-commissioning verification of abatement equipment (e.g., thermal oxidizers, activated carbon beds) via upstream/downstream differential measurements
• Educational demonstrations of gas-phase reaction kinetics and stoichiometric quantification principles in university environmental engineering labs

FAQ

What is the shelf life of the 187S tube, and how should it be stored?
Unopened tubes retain accuracy for 24 months from manufacture date when stored between 5 °C and 30 °C in original aluminum pouches, away from direct sunlight and strong oxidizers.
Can the 187S tube be used for quantitative regulatory reporting?
No—it is intended for screening and semi-quantitative estimation only. Regulatory-grade NMHC data require EPA Method 25A, TO-15, or ISO 11890-2 compliant instrumentation with full QA/QC documentation.
Is the AP-20 hand pump included with the 187S tube?
No—the AP-20 pump is sold separately and must be calibrated annually per Meiko Rika Technical Bulletin TB-AP20-Rev.4.
Does humidity affect measurement accuracy?
Yes—relative humidity above 85% may cause slight retardation of color front progression; correction factors are supplied in the product insert for RH 60–95%.