Water Vapor Transmission Rate Analyzer

W-B-11-B

Water Vapor Transmission Rate Tester (Gravimetric Method)

                             Compact ASTM E96 Cup Method WVTR Tester for Films, Textiles and Building Materials

Product Overview

The LabStone Gravimetric Water Vapor Transmission Rate Tester is a compact, high-precision instrument designed for determining the water vapor transmission rate (WVTR), water vapor permeability, and moisture barrier performance of films, sheets, textiles, leather, paper, containers, and construction materials.

Based on the internationally recognized gravimetric cup method, the system provides reliable and traceable measurements for laboratories engaged in material research, product development, quality control, and standards compliance testing.

Its compact footprint, simple operation, and low operating cost make it an ideal solution for universities, research institutes, quality laboratories, and manufacturers of breathable or moisture-resistant materials.

Function:

Determining water vapor permeability characteristics of materials and containers.

Suitable for: Film, sheet, container, and construction material of plastic, textile, leather, and metal.

Principle:

The instrument adopts the Gravimetric Cup Method in accordance with ASTM E96, ISO 2528, GB/T 1037 and other internationally recognized standards.

Water is placed inside a specially designed test cup, and the specimen is sealed over the cup opening.

The cup is then placed inside a temperature- and humidity-controlled chamber.

A water vapor pressure difference is established across the specimen, causing water vapor to permeate through the material.

As moisture escapes from the cup, the cup mass gradually decreases.

The analytical balance continuously records weight changes, and the software automatically calculates:

• Water Vapor Transmission Rate (WVTR)
• Water Vapor Permeability
• Water Vapor Permeability Coefficient

Both upright cup and inverted cup testing methods are supported.

Compliant Standards:

The instrument complies with the latest versions of internationally recognized water vapor permeability standards:

• ASTM E96 / ASTM E96M
• ISO 2528
• GB/T 1037
• GB/T 17146
• GB/T 12704.1
• QB/T 2414       

Key Features

ASTM E96 Compliant Gravimetric Method

The instrument follows internationally accepted cup method principles and is suitable for regulatory, quality control, and research applications.

High-Precision Analytical Balance

Equipped with:

• 210 g weighing capacity
• 0.1 mg resolution

ensuring accurate detection of small weight changes during long-term permeability testing.

Patented Test Cup Design

Specially engineered test cups feature:

• Plastic-free exterior to eliminate moisture absorption effects
• Anti-slip specimen support structure
• Reliable sealing performance
• Improved repeatability

The design minimizes measurement uncertainty caused by cup deformation or environmental influence.

Automatic Temperature and Humidity Control

Temperature control range:

• 10°C to 45°C

Humidity control range:

• 5% RH to 35% RH

Automatic environmental control ensures stable testing conditions and improved reproducibility.

Uniform Airflow Technology

A dual-plane spiral air circulation system provides:

• Uniform airflow distribution
• Stable humidity field
• Consistent temperature field

which significantly improves test repeatability.

Analytical Balance Protection System

Patented protection technology shields the balance from:

• Heat
• Moisture
• Corrosive environments

ensuring long-term stability and service life.

Fully Automated Operation

Features include:

• One-button testing
• Automatic test execution
• Automatic result calculation
• Automatic data storage
• Automatic test completion

No manual intervention is required during routine testing.

Intelligent Self-Diagnosis

The system automatically performs startup diagnostics to identify abnormal operating conditions before testing begins.

GMP-Compliant Data Management

Optional GMP Computerized System software provides:

• User access management
• Electronic records
• Audit trails
• Data integrity protection

supporting pharmaceutical and regulated laboratory environments.

Specification:

Configuration: Principal machine, air dryer tube, professional software, test cupes, Correction weight(200g), Specimen Sampler.

Optional: computer, GMP Software module, asphalt-seal cup.

Self-Supply: Compressed air, distilled water.

Applications

Building Materials Industry

Widely used for evaluating moisture transmission properties of:

• Roofing membranes
• Waterproof membranes
• Vapor barriers
• Building wraps
• Thermal insulation materials
• Waterproof coatings

Testing helps determine condensation resistance and moisture management performance in building envelopes.

Textile and Apparel Industry

Suitable for:

• Functional fabrics
• Outdoor clothing materials
• Sportswear membranes
• Breathable textiles
• Medical textiles

Used to evaluate moisture vapor transmission and wearer comfort.

Packaging Industry

Applicable to:

• Plastic films
• Composite packaging materials
• Paper packaging
• Sustainable packaging materials

Supports moisture barrier evaluation and packaging optimization.

Research and Academic Laboratories

Ideal for:

• Material comparison studies
• Barrier property research
• Standards verification
• New material development
   

Typical Materials Tested

The instrument is suitable for testing:

Plastic Films

• PE
• PP
• PET
• PVC
• EVOH composite structures

Textile Materials

• Breathable fabrics
• Functional membranes
• Medical textiles

Paper and Fiber Materials

• Coated paper
• Packaging paper
• Specialty papers

Construction Materials

• Roofing membranes
• Waterproof barriers
• Building wraps
• Insulation materials

Leather and Synthetic Leather

• Natural leather
• PU leather
• Functional synthetic materials

Frequently Asked Questions (FAQ)

What is the gravimetric method for WVTR testing?

The gravimetric method determines water vapor transmission by measuring the weight change of a test cup under controlled environmental conditions.

What is the difference between the upright cup and inverted cup methods?

The two methods establish different humidity gradients across the specimen and are selected according to specific testing standards and material types.

Is ASTM E96 still widely used?

Yes. ASTM E96 remains one of the most widely recognized methods for evaluating water vapor transmission in construction materials, textiles, and packaging materials.

Can breathable fabrics be tested?

Yes. The instrument is commonly used for evaluating moisture vapor transmission performance of sportswear, outdoor fabrics, and medical textiles.

Can building materials be tested?

Yes. Roofing membranes, vapor barriers, insulation materials, and waterproof coatings are among the most common applications.

Does the instrument require a climate-controlled laboratory?

No. The system includes its own environmental control system and can operate in a standard indoor laboratory environment.

Can the instrument be used for pharmaceutical packaging materials?

Yes. With the optional GMP software module, it can support pharmaceutical packaging permeability studies and regulatory documentation.

What other names are commonly used for this product?

English

• Gravimetric WVTR Tester
• ASTM E96 WVTR Tester
• Cup Method Water Vapor Transmission Rate Tester
• Water Vapor Permeability Tester
• Moisture Vapor Transmission Tester
• WVTR Testing Equipment

Spanish

• Analizador de Permeabilidad al Vapor de Agua por Método Gravimétrico

Portuguese

• Testador Gravimétrico de Taxa de Transmissão de Vapor de Água

French

• Analyseur Gravimétrique de Transmission de Vapeur d’Eau

German

• Gravimetrisches Wasserdampfdurchlässigkeitsprüfgerät

Japanese

• 重量法水蒸気透過率試験機