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Oxygen Transmission Rate (OTR) Tester - Isobaric Coulometric oxygen permeation tester

Oxygen Transmission Rate (OTR) Tester - Isobaric Coulometric oxygen permeation tester

Model: UT2108E; ISO 15105-2, ASTM D3985, ASTM F1927, ASTM F1307

UT2108E Coulometric Oxygen Transmission Rate Tester, also called the Isobaric Coulometric OTR Tester or Oxygen Permeability Tester, is based on the electrochemical coulometric detection principle. It provides high-precision and efficient oxygen transmission rate testing for materials with high or medium barrier properties. It's suitable for testing the oxygen permeability of films, sheets, and related materials in industries like food, pharmaceuticals, daily chemical products, and electronics. It measures the permeation of oxygen gas alone under equal pressure on both sides, making it an arbitration-level testing device for plastic packaging, pharmaceutical packaging, and high-barrier films. 

Key testing indicators include Oxygen Transmission Rate (OTR), oxygen volume passing through, permeation curves, and equilibrium time, with the ability to calculate permeation coefficients simultaneously. With container fixtures, it can test the total oxygen transmission of plastic bottles and flexible packaging bags. 


Applicable materials: It can test oxygen transmission rates for a wide range of materials, including various plastic films, high-barrier materials, solar back sheets, photovoltaic back sheets, sheets, composites, shrink films, aluminum-coated films, co-extruded films, aluminum foil, aluminum-plastic composite rigid sheets, slab materials, as well as packaging containers like bottles, bags, cans, and boxes made from plastics, rubber, paper, glass, metal, and pharmaceutical packaging materials.


Conform with standard: ISO 15105-2 Plastics - Film and sheeting - Determination of gas transmission rate - Part 2: Equal-pressure method

ASTM F1307 Standard Test Method for Oxygen Transmission Rate Through Dry Packages Using a Coulometric Sensor

ASTM D3985, ASTM F1927, DIN 53380-3, JIS K 7126-2

General introduction

UT2108E Isobaric Coulometric OTR Tester | High Precision Oxygen Permeability Analyzer

The UT2108E Coulometric Oxygen Transmission Rate Tester, widely known as an isobaric coulometric OTR tester or oxygen permeability tester, adopts the advanced electrochemical coulometric detection method. This arbitration-grade testing equipment delivers accurate, time-efficient oxygen transmission rate analysis for medium and high barrier packaging materials.

Operating under balanced equal pressure on both specimen sides, the machine exclusively quantifies oxygen gas permeation. It serves routine quality control, material R&D and third-party arbitration testing across food packaging, pharmaceutical packaging, daily chemical and electronic manufacturing sectors.


Core measurable test parameters cover Oxygen Transmission Rate (OTR), cumulative oxygen permeation volume, real-time permeation curves and test equilibrium duration. The system auto-computes oxygen permeation coefficients for full material barrier performance evaluation. Equipped with dedicated container testing fixtures, the unit accurately detects total oxygen transmission of finished plastic bottles and flexible packaging pouches.

Wide Compatible Test Specimens

This isobaric OTR tester supports oxygen barrier testing for extensive substrates and finished packaging containers:

Plastic films, high-barrier films, solar back sheets, photovoltaic back sheets, plastic sheets, multi-layer composite films, heat shrink films, metallized aluminum-coated films, co-extruded films, aluminum foil, rigid aluminum-plastic composite slabs, and packaging vessels including plastic, rubber, paper, glass, metal bottles, bags, cans and pharmaceutical packaging products.

Oxygen Transmission Rate (OTR) Tester - Isobaric Coulometric oxygen permeation testerOxygen Transmission Rate (OTR) Tester - Isobaric Coulometric oxygen permeation tester


Global Authoritative Test Standard Compliance

The UT2108E oxygen permeability analyzer fully complies with international isobaric oxygen transmission testing standards:

ISO 15105-2 Plastics - Film and sheeting - Determination of gas transmission rate - Part 2: Equal-pressure method

ASTM F1307 Standard Test Method for Oxygen Transmission Rate Through Dry Packages Using a Coulometric Sensor

ASTM D3985, ASTM F1927, DIN 53380-3, JIS K 7126-2


Design theory:

The pre-treated sample is clamped between the upper and lower test chambers of the instrument, and the required temperature, humidity, and flow rate for the test are set. Nitrogen with stable relative humidity flows on one side of the film, while dry nitrogen flows on the other side. Due to the concentration difference (partial pressure), oxygen diffuses through the film from the high concentration side to the low concentration side. On the low concentration side, the oxygen that passes through is carried by the flowing dry nitrogen to the sensor, which detects the oxygen content and then calculates the oxygen transmission rate of the sample.


Keywords: UT2108E coulometric oxygen transmission rate tester, isobaric OTR tester, oxygen permeability analyzer, Coulometric Oxygen Transmission Rate (OTR) Tester, electrochemical coulometric detection, equal-pressure oxygen permeation test, arbitration-grade packaging tester, isobaric coulometric oxygen permeation tester, photovoltaic back sheet barrier test, metallized film OTR measurement, plastic bottle total oxygen transmission test, oxygen Transmission Rate Test System, pharmaceutical packaging oxygen barrier testing

Key Features

  • Test principle
  • Main features
  • Overall Structure and Subcomponents
  • Application
  • Standard
  • Complete Test Procedure
  • Sample Requirements and Pre-Treatment

The film sample is sealed in a split test chamber, divided into an oxygen supply side (upper chamber) and a carrier gas side (lower chamber). Both sides are at normal pressure with no pressure difference, relying only on the oxygen concentration difference to drive permeation.  


High-purity oxygen (99.99%) is continuously fed into the upper chamber, while high-purity nitrogen is used as the carrier gas in the lower chamber.  

Oxygen that passes through the film is carried by the nitrogen into a built-in coulometric sensor.  


Inside the sensor, the permeated oxygen undergoes an electrochemical reaction, generating a tiny current proportional to the volume of oxygen.  


The control system uses Faraday's law of electrolysis to continuously calculate the amount of oxygen passing through per unit time and per unit area, recording the values in real time. Once the curve stabilizes, a steady state is determined, and the final OTR result is output.



• Features a three-chamber parallel flat design, making it easy to apply sealing grease, place samples, and check if they are level and centered.  

• Equipped with a 10-inch touchscreen high-end industrial computer, ensuring reliable operation and secure data storage (desktop PC option available).  

• Supports main machine and satellite machine combination (expandable up to 9 units), allowing up to 30 stations to test simultaneously.  

• Imported brand Coulomb oxygen sensing system with multi-channel signal acquisition chips.  

• Ultra-high resolution and ultra-low baseline zero with minimal zero drift.  

• Excellent fluid and thermal design ensures top-level uniformity and control of temperature and humidity within the test chamber.  

• Supports simultaneous testing of three samples under the same conditions, with independent data for each (3 stations at once).  

• Main and satellite machine mode supported, expandable to 9 satellite machines, enabling 30 samples to be tested at the same time.  

• Equipped with high-precision temperature and humidity sensors for real-time monitoring and recording of changes.  

• Automated control of flow, temperature, and relative humidity during testing.  

• Top cover can be manually flipped or operated with a one-touch smart auto-flip.  

• Menu-style interface, with independent menus for each test function, making parameter setting and testing easy.  

• Login with startup password to prevent unauthorized use, with four levels of permission management.  

• Supports exporting test data in multiple file formats and file verification.  

• Optional professional GMP computer communication software can implement data traceability, multi-level permission management, audit tracking, electronic signatures, and more.

1. Constant Temperature and Humidity Test Chamber Module (Main Unit Core)

Independent three-chamber structure, three groups of samples can be tested simultaneously, data does not interfere with each other;

The chamber is made of 316 stainless steel, with pneumatic uniform compression and sealing, and an annular silicone sealing ring to prevent air leakage at the edges.

Standard effective test area: 50cm², suitable sample thickness: 0.01~3mm;

PID constant temperature system: temperature control range 10°C~60°C, temperature control accuracy ±0.1°C, chamber temperature uniformity ±0.3°C;

Built-in wet and dry gas mixing circuit, continuously adjustable humidity 0~95% RH, meeting wet testing requirements for nylon and EVOH hydrophilic films;

Independent air duct ensures uniform air purging of the sample surface, with no airflow disturbance affecting the detection signal.


2. High-precision coulomb sensor detection module (core precision component)

Original electrochemical coulombic oxygen sensor for precise identification of trace amounts of oxygen;

Measurement range: 0.01~200 (cm3/(m2·24h)), minimum detection limit 0.01;

Comes with an automatic calibration program, supporting one-click calibration of standard calibration membranes to meet CNAS metrology traceability;

Signal acquisition frequency is 10Hz, real-time output instantaneous OTR, and a complete record of the entire penetration process curve;

Service life is 2~3 years, and replacement is simple.


3. Precision pneumatic circuit control unit

Dual independent gas circuits: oxygen intake circuit, nitrogen carrier gas circuit;

High-precision MFC mass flow meter, adjustable gas flow rate 0.1~100mL/min, flow fluctuation ≤±0.2mL/min;

The solenoid valve automatically switches between purge and test modes, fully automatically removing residual oxygen from the chamber before testing, shortening balancing time;

The pipeline uses Teflon stainless steel, with no oxygen adsorption and no baseline drift during micro-detection.

Food Packaging Industry  

Testing of fresh-keeping MAP bags, high oxygen barrier composite films for nuts, juice bottles, vacuum bags for cooked food, and POF cross-linked shrink films; optimizing formulas through OTR data to extend food shelf life and prevent fat oxidation or food from molding and discoloring.  


Pharmaceutical Packaging (Mandatory Demand)  

Pharmaceutical PVC rigid sheets, aluminum-plastic blister packs, sterile medical device packaging bags, infusion bags; compliant with YBB pharmaceutical packaging standards, used as specialized equipment for annual inspections by pharmaceutical companies and drug inspection institutes.  


Film Manufacturing Companies  

Factory QC for BOPA, BOPET, co-extruded EVOH films, metallized films, and coated barrier films; adjust extrusion, lamination, and coating processes, manage oxygen barrier indicators.  


New Material Research & University Labs  

Development of high barrier modified formulations, research on oxygen barrier performance for photovoltaic solar back sheets, lithium battery outer packaging films, and optical protective films.  


Third-Party Testing Agencies & Quality Inspection Institutes  

Undertake product type inspections and export commissioned testing, issue arbitration-grade inspection reports; for high barrier materials, oxygen permeability tests under national standards preferably use the coulometric method.  


Daily Chemical & Cosmetic Industry  

High barrier bottles for serums, cream tube packaging, preventing skincare products from oxidizing and spoiling.


ISO 15105-2 Plastics - Film and sheeting - Determination of gas transmission rate - Part 2: Equal-pressure method

ASTM D3985 Standard Test Method for Oxygen Gas Transmission Rate Through Plastic Film and Sheeting Using a Coulometric Sensor

ASTM F1307 Standard Test Method for Oxygen Transmission Rate Through Dry Packages Using a Coulometric Sensor

ASTM F1927 Standard Test Method for Determination of Oxygen Gas Transmission Rate, Permeability and Permeance at Controlled Relative Humidity Through Barrier Materials Using a Coulometric Detector

DIN 53380-3 Testing of plastics - Determination of gas transmission rate - Part 3: Oxygen-specific carrier gas method for testing of plastic films and plastics mouldings

JIS K 7126-2 Plastics -- Film and sheeting -- Determination of gas-transmission rate -- Part 2: Equal-pressure method

GB/T 1038.2 Plastics—Film and sheeting—Determination of gas-transmission rate—Part 2:Equal-pressure methods

GB/T 19789 Packaging material—Test method for oxygen gas permeability characteristics of plastic film and sheeting—Coulometric sensor

GB/T 31354 Determination of oxygen gas transmission rate through dry packages.Coulometric sensor

Equipment Startup and Preheating

Turn on the power, open the oxygen and nitrogen gas sources, set the test temperature and humidity, automatically purge the gas lines for 30 minutes to remove residual oxygen, and stabilize the baseline.


Sample Clamping and Sealing

Place the three pre-treated samples into three separate chambers, activate pneumatic clamping to seal, and input the sample name, thickness, and batch number into the system.


Start Fully Automatic Test

The equipment automatically switches to the test gas path, with oxygen continuously entering the upper chamber while nitrogen carries permeated oxygen to the sensor; the software collects the OTR dynamic curve in real time.


Automatic Steady-State Detection

The system continuously monitors the slope of the curve; when the value remains stable for a long time without fluctuation, it automatically determines that permeability has reached equilibrium and stops data collection.


Automatic Data Calculation

Automatically calculate the average OTR and standard deviation of the three sample sets, and generate a test report containing temperature and humidity, test duration, and the complete permeability curve.


Save / Export Report

The curves and raw data are permanently stored locally, with options to print paper reports or export electronic files for archiving; after the test is complete, the system automatically depressurizes and the samples can be removed.


1. Sample Size

Cut 100mm×100mm square film samples, ensuring no pinholes, scratches, wrinkles, or oil stains; hard sheets and aluminum-plastic sheets should be flat and free of deformation.


2. Conditioning (Mandatory According to National Standards)

Place the samples in a standard environment: temperature 23℃, relative humidity 50% RH, and let them sit for at least 4 hours to relieve internal stress and balance moisture content.


3. Number of Samples

Each test group should have at least 3 parallel samples. If using a three-station instrument, it can test the parallel samples at once and automatically calculate the average and standard deviation.

Main Technical Specification

Test stationStandard includes 1~3 workstations (can expand with satellite units)
Testing range0.01-200 cm³/(m²·day) (standard); 0.01 ~ 10000 cm³/(m²·day) (optional). Others can be customized through MASK or chamber size
Testing resolution0.001 cm³/(m²·day)
Temperature control range10℃~55℃ (standard), others can be customized
Temperature resolution0.01℃
Humidity control rangeOxygen 0%, 5–90% ±1% RH (within standard temperature range), 100% Carrier gas 0%, 5–90% ±2% RH (requires additional purchase)
Humidity accuracy±1% RH
Sample thickness≤3 mm (other thicknesses can be customized)
Test area50 cm²
Carrier gas requirements99.999% ultra-pure nitrogen (gas supply not included, 5N purity)
Gas pressure≥ 280 kPa
Interface size1/8” metal tube
Dimensions680 mm (L) × 490 mm (W) × 620 mm (H)
Power supplyAC 220V 50Hz / 110V, 60HZ
Net weight100 kg


Main Accessories

Standard configuration: Main unit (with touch industrial computer), round sampler, air supply valve fittings (built-in). 


Optional items: Online satellite machine, standard membrane (purchased on behalf of the Central Inspection Institute), air compressor, GMP computer system requirements (computer to be provided by the user).

Standard

ISO 13636 Non-oriented PET Films sheeting test requirement (APET)

ISO 13636 specifies requirements anf test methods for non-oriented PET (APET) sheets — made from virgin, recycled, or combined PET, thickness < 2.0 mm. It explicitly excludes foamed sheets and shrinkable films (those are covered elsewhere, e.g. biaxially oriented PET in ISO 15988). The mandatory performance tests including Tensile stress at yield, Heat shrinkage, Oxygen transmission rate (OTR), haze value, Intrinsic viscosity (IV).

ISO 15988 Biaxial stretch PET films test methods details

ISO 15988 specifies requirements for biaxially oriented transparent PET (BOPET) films, mainly used for packaging, either alone or as a laminated layer with other films. The main test stipualted in this standard include tensile strength and strain, Dimensional change on heating, Oxygen transmission coefficient, Water vapour transmission coefficient, Haze, Wetting tension, thickness etc., 

ISO 15987 Biaxially oriented nylon films tensile expansion testing methods

ISO 15987 specifies classification, mandatory visual, dimensional, mechanical, barrier, optical, surface energy, and food contact safety requirements for transparent BOPA film, supplied in roll form, either used standalone or laminated with PE, CPP, PET, aluminium foil for multi-layer packaging structures. The test stipulated in ISO 15987 mainly include, tensile strength & tensile strain at break, Oxygen transmission coefficient, Dimensional change on heating, Haze, Wetting tension etc., 

ISO 17555 BOPP films biaxial stretch testing methods

ISO 17555 applies to packaging-grade BOPP films containing ≥95% polypropylene resin; usable as single-layer film or laminates paired with other plastic substrates. The test stipulated in ISO 17555 mainly include, tensile strength & strain at break, Dimensional change on heating (thermal shrinkage), Coefficient of water vapour transmission, Haze, Wetting tension etc., 

​Coulometric Method vs Pressure Difference Method: Key Comparison and Advantages


Contrast dimensionsCoulometric isobaric oxygen permeabilityDifferential pressure method permeable testerExplanation of the advantages of the Coulometric method
Applicable gasesOxygen only (specialized high precision)Compatible with multiple gases such as O₂, CO₂, and N₂Oxygen detection is highly specific, with no interference from other gases, and the precision is based on the rolling pressure differential method
Minimum   detection limit0.010.5Ultra-high barrier aluminum foil / EVOH membranes can only be accurately measured by the Coulometric method, while the differential pressure method has very large errors
Testing   environmentPrecise temperature control + humidity control at 0~95% RHBasic models do not have humidity adjustmentIt can simulate humid storage environments, and hydrophilic membrane test data is authentic and reliable
Test duration0.5~2h4~24hVacuum extraction steps increase balancing speed several times and high efficiency for large-scale inspection
Core systemNo vacuum pump, isobaric environmentTwo-stage vacuum extraction systemNo maintenance issues such as vacuum pump oil replacement or pipeline leaks, resulting in a low failure rate
Arbitration   qualificationsGB/T, YBB, ASTM specify arbitration methodsMedium to low breathable materials are available; high barrier materials are not   acceptedExport, drug inspection, and dispute arbitration must use the Coulometric method
Baseline stabilityGas purging removes residues, stabilizing the baselineVacuum is prone to leakage and baseline driftTrace oxygen detection offers superior repeatability and reproducibility
Applicable   scenariosHigh-barrier films, pharmaceuticals, food, export testingOrdinary PE film, carbonate packaging, CO₂/N₂ measurementThe preferred testing equipment for the high-barrier packaging industry for food and pharmaceuticals
Data reliabilityElectrochemical direct quantitative oxygen with minimal interferenceRelying on pressure boost rate for conversion makes it susceptible to air leakageParallel sample data have low dispersion and better repeatability


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