Fully Automatic Oxygen Index Tester Launched, Delivering Closed-Loop Precision LOI Testing per GB/T 2406

New JYZS-20 fully automatic oxygen index tester with touch screen closed-loop control, high-precision stepper proportional valve, complies with GB/T 2406 for plastic, textile, fire door limiting oxygen index flammability testing.

August 3, 2026 – A professional manufacturer of fire safety testing instruments today unveiled the JYZS-20 Fully Automatic Oxygen Index Tester, an upgraded limiting oxygen index (LOI) testing system engineered to eliminate manual gas adjustment errors and deliver industry-leading measurement stability for polymer, textile and construction material flammability assessment. Designed strictly in accordance with GB/T 2406 standard for plastics burning behaviour testing, this automatic LOI apparatus serves material labs, plastic manufacturers, fire retardant R&D teams and third-party certification facilities worldwide.

Limiting oxygen index testing is the core quantitative method to evaluate material flame resistance: the higher the LOI value, the harder the material catches fire and sustains combustion. Traditional manual oxygen index testers require operators to repeatedly tweak oxygen and nitrogen flow during testing, leading to oxygen concentration drift and inconsistent test results. The JYZS-20 solves this long-standing pain point via fully automatic closed-loop gas control architecture, drastically boosting test repeatability and operational efficiency.

Core Automatic Control Innovations of JYZS-20

Full-Color Touch Screen One-Click Operation

Operators simply input the target oxygen concentration on the integrated touch panel. The system automatically mixes oxygen and nitrogen, stabilizes the gas ratio and triggers an audio alert once the set value is reached. No tedious manual valve adjustment is required, cutting sample preparation time by over 60%.
Stepper-Driven Proportional Valve + Closed-Loop Drift Correction

Equipped with high-precision stepper proportional valves and imported digital oxygen sensors, the tester continuously monitors real-time oxygen concentration throughout the test. If concentration drifts, closed-loop logic instantly corrects flow rates to restore the target O₂ level — a key upgrade unavailable on conventional manual LOI devices. This design eliminates measurement deviation caused by gas pressure fluctuation and guarantees ±0.1% resolution accuracy.
Ultra-Fast Response & Stable Gas Delivery

The oxygen sensor response time is controlled within 5 seconds, with a full 0–20 L/min flow adjustment range. Built-in dual pressure stabilizing valves, precision flow regulators, gas filters and mixing chambers ensure consistent 40 ± 2 mm/s airflow velocity inside the 75 mm inner diameter combustion column, fully meeting GB/T 2406 airflow requirements.

Complete Technical Specifications Aligned with GB/T 2406 Standard

Oxygen measuring range: 0–100% with direct digital readout, no manual calculation
Measurement resolution: ±0.1% oxygen concentration
Combustion column: 75 mm inner diameter, 500 mm height
Ignition system: Propane/butane torch with adjustable flame length (5–60 mm, standard 16 ± 4 mm)
Dual specimen holders: Self-support frame for rigid plastics, clamping frame for flexible films & textiles
Operating environment: -10°C ~ 45°C, relative humidity below 85%
Power supply: 220V / 50Hz, rated power 100W
Gas requirement: Industrial O₂ & N₂ purity ≥99%, inlet pressure 0.2–0.3 MPa

Wide Application Coverage

The JYZS-20 oxygen index tester supports LOI testing for diverse materials as specified in GB/T 2406:

Rigid & flexible plastic raw materials, plastic films, foam plastics
Textile fabrics, fiber yarns, composite nonwovens
Fire-resistant door panels, insulation boards, building decorative sheets
Rubber, cable insulation layers, new energy battery separators
Fire retardant formulation research and batch quality inspection

Stable, User-Friendly Lab Design

The all-in-one cabinet integrates gas mixing, pressure regulation and test combustion units for compact lab placement. Dual pressure gauges visually display oxygen and nitrogen pipeline pressure, while interchangeable specimen holders adapt to different sample shapes without extra accessories. The tester only requires standard industrial oxygen and nitrogen cylinders for operation, with low daily maintenance costs.

Target End Users

Plastic compounding & masterbatch manufacturers
Fire retardant chemical R&D laboratories
Third-party fire safety certification institutes
Textile, automotive interior and construction material factories
University material science & fire engineering research labs

About Our Instrument Division

We specialize in manufacturing a full lineup of fire performance testing equipment, including oxygen index testers, cone calorimeters, cable flame test machines and pipe hydrostatic pressure systems. All products comply with Chinese GB standards and matching international ISO/ASTM specifications, with global after-sales support, calibration services and customized lab layout solutions.

For full technical datasheets, pricing and lab trial demonstration requests, visit our official website and submit an online inquiry form.