KOMYO CO₂ Gas Detection Tube (Model 126SF)

Overview

The KOMYO CO₂ Gas Detection Tube (Model 126SF) is a single-use, colorimetric chemical indicator device engineered for rapid, on-site quantification of carbon dioxide (CO₂) concentration in ambient or workplace air. It operates on the principle of stoichiometric gas-phase reaction: CO₂ diffuses through a calibrated glass tube containing a chemically impregnated silica gel reagent layer. Upon contact, CO₂ reacts with alkaline reagents—typically barium hydroxide or sodium hydroxide derivatives—forming a carbonate precipitate that induces a sharp, linear color front progression along the tube’s internal scale. The length of the stained zone, measured in millimeters from the inlet end, corresponds directly to the CO₂ concentration (in % vol or ppm), as pre-calibrated under standardized temperature (20 °C), pressure (101.3 kPa), and sampling volume conditions. Designed for field deployment in industrial hygiene, confined-space entry verification, HVAC commissioning, and indoor air quality (IAQ) surveys, this detection tube requires no power source, electronics, or calibration maintenance—making it intrinsically safe for use in explosive or electrically hazardous environments.

Key Features

• Direct-reading visual quantification: Linear color development enables immediate concentration determination without instrumentation
• Pre-calibrated for CO₂ across a defined range (0.1–5.0% vol), traceable to NIST-traceable reference gases
• Compatible exclusively with the KOMYO AP-20 dual-stroke hand pump (100 mL stroke volume, ±5% volumetric accuracy per ISO 8519)
• Single-use design ensures measurement integrity—no cross-contamination or reagent degradation between tests
• Robust borosilicate glass construction with laser-etched scale (0.1 mm resolution) and protective outer sleeve
• No electrical components, batteries, or ignition sources—certified for Class I, Division 2 hazardous locations per NEC Article 500

Sample Compatibility & Compliance

The 126SF tube is validated for use in clean, dry, non-corrosive air matrices. It is not recommended for sampling in high-humidity (>85% RH), high-particulate, or acidic gas environments (e.g., SO₂, NOₓ >10 ppm), which may interfere with reagent stability or front definition. Each production lot undergoes batch certification per JIS K 0111 (Japanese Industrial Standard for Gas Detection Tubes) and conforms to ISO 8519:2017 “Air quality — Determination of gases — Use of detector tubes”. Documentation includes lot-specific calibration certificates, shelf-life validation (24 months unopened at 5–30 °C), and compliance with REACH Annex XIV SVHC screening. For occupational exposure assessment, results are applicable under OSHA 29 CFR 1910.1200 (HCS) and ACGIH TLV® methodology guidelines.

Software & Data Management

As a passive, analog measurement system, the 126SF detection tube does not interface with software, data loggers, or digital networks. All measurements are manually recorded via field logbooks or printed checklists aligned with ISO/IEC 17025 documentation requirements. Users are advised to retain used tubes (with annotated date/time/location/stamp) for audit trails. When integrated into formal monitoring programs, data entry into LIMS or EHS platforms must follow documented SOPs specifying observer name, pump strokes, ambient T/P, and tube lot number—supporting GLP-compliant record retention for up to 5 years.

Applications

• Confined space entry pre-testing (e.g., fermentation tanks, silos, utility vaults) per OSHA 1910.146
• Routine IAQ audits in schools, offices, and healthcare facilities to verify ASHRAE 62.1 ventilation rates
• Leak detection in CO₂-based fire suppression systems and beverage carbonation lines
• Validation of scrubber efficiency in biogas upgrading or fermentation off-gas treatment
• Emergency response triage during transportation incidents involving dry ice or CO₂ cylinders
• Educational demonstrations of gas diffusion kinetics and acid-base reaction stoichiometry

FAQ

What is the shelf life of an unopened 126SF tube?
24 months from date of manufacture when stored at 5–30 °C in original packaging, protected from light and moisture.
Can the same AP-20 pump be used for other KOMYO detection tubes?
Yes—the AP-20 is compatible with all KOMYO tubes requiring 100 mL total sampling volume; however, stroke count and timing must follow each tube’s specific instruction sheet.
Is this tube suitable for measuring CO₂ in flue gas or combustion exhaust?
No—high temperature (>50 °C), moisture, and co-existing acidic gases will compromise reagent performance and color front clarity.
Does the reading require temperature correction?
Yes—correction factors are provided in the product manual for measurements conducted outside 20 ±2 °C; deviations beyond ±5 °C invalidate stated accuracy.
How is measurement uncertainty determined for this method?
Per JIS K 0111, expanded uncertainty (k=2) is ±12% of reading for concentrations ≥0.5% vol, increasing to ±25% near the lower detection limit (0.1% vol).