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How to Choose a Temperature and Humidity Chamber Meeting -70℃ for Composite Materials Testing

Jan 28 2026

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The “Environmental Memory” of Composite Materials

Composite materials are highly sensitive to temperature and humidity. Before conducting mechanical tests such as tensile, compression, or bending, environmental conditioning is crucial to ensure reliable and reproducible results. Minor variations in temperature or humidity can significantly impact material performance, particularly in high-end applications like aerospace and deep-sea exploration.

The Significance of -70℃

For aerospace, deep-sea, and extreme environment applications, -70℃ is not just a low temperature—it represents a realistic simulation of harsh operating conditions. Only a temperature and humidity chamber capable of reliably reaching -70℃ can accurately evaluate the low-temperature performance of composite materials.

Common Challenges

Conventional chambers often struggle under extreme low temperatures, resulting in:

Large temperature drift affecting test accuracy
Failure of humidity control due to frosting
Slow cooling rates, extending test cycles

A high-quality temperature and humidity chamber can overcome these limitations. LIB industry’s ultra-low temperature chambers provide a stable, precise, and reproducible testing environment, ensuring reliable composite materials testing results.

Key Selection Criteria for a Temperature and Humidity Chamber

1. Cooling System — The Heart of the Chamber

Achieving ultra-low temperatures relies on cascade refrigeration technology. Compared with single-stage compressors, cascade systems can:

Stably reach -70℃
Achieve rapid cooling rates
Use environmentally friendly refrigerants

LIB industry cascade refrigeration systems ensure rapid, stable cooling from room temperature to -70℃, guaranteeing the accuracy and efficiency of composite materials mechanical testing.

2. Humidity Control at Extreme Low Temperatures

Low temperatures make humidity control challenging, as moisture tends to freeze. Selection criteria include:

Anti-frost design
Fast-response dehumidification
Precision chamber sealing and heat-stress-resistant materials

LIB industry temperature and humidity chambers feature multi-layer vacuum insulated observation windows and high-density polyurethane insulation, maintaining stable humidity even at -70℃.

3. Uniformity and Fluctuation — Ensuring Reliable Test Data

Referenced Standards: ASTM D5229, GB/T 2573
Forced air circulation design ensures uniform temperature and humidity across the chamber

LIB industry chambers are optimized for airflow distribution, achieving ±0.5℃ temperature uniformity to ensure consistent test results for all composite material samples.

Special Requirements for Composite Materials Testing

High-Precision Sensors

Using PT100 high-precision sensors ensures accurate temperature and humidity measurements.

Data Recording and Traceability

Supports USB data export and remote control, meeting laboratory accreditation requirements and ensuring full traceability of experimental data.

Sample Rack Design

Optimized internal layout allows efficient placement of multiple composite material specimens while maintaining airflow uniformity.

LIB industry offers customizable sample racks to maximize space utilization and test efficiency for batch composite testing.

Composite Materials Testing Process and Standards

Typical Testing Process

Sample Preparation: Cut composite material specimens to standard dimensions according to ASTM or GB/T guidelines and label each sample.
Environmental Conditioning: Place samples in the temperature and humidity chamber at the target temperature (e.g., -70℃) and humidity, allowing the material to reach equilibrium.
Mechanical Testing: Conduct tensile, compression, or bending tests under stable conditions to ensure reliable data.
Data Recording and Analysis: Use built-in sensors or external devices to monitor temperature and humidity, generating a complete traceable data chain.

Referenced Standards

ASTM D5229 / D5529M: Moisture absorption and mechanical performance testing for composite materials
GB/T 2573: Environmental testing methods for composite materials
ISO 9142 / ISO 14126: Conditioning and environmental performance testing

LIB industry chambers support full environmental simulation and data recording, ensuring compliance with international and domestic testing standards for research and quality certification purposes.

Laboratory Deployment Recommendations

Power Requirements

Ultra-low temperature chambers consume high power; confirm laboratory electrical capacity in advance.

Space for Heat Dissipation

Cascade refrigeration systems generate significant heat; provide adequate maintenance and ventilation space.

After-Sales Support and Technical Services

Extreme low-temperature equipment is complex; evaluate manufacturer maintenance and support capabilities.

Choosing LIB industry temperature and humidity chambers ensures:

3-year warranty
Lifelong technical support
24/7 English-speaking service
Globally stocked spare parts
Professional commissioning and installation

Guaranteeing safe, efficient, and continuous operation for every composite materials test.

Conclusion and Call to Action

Summary

Selecting a high-quality temperature and humidity chamber is more than purchasing hardware—it is an investment in data stability and test reliability. LIB industry ultra-low temperature chambers provide precise environmental simulation, standardized testing procedures, and reliable data traceability.

Call to Action

If your laboratory is planning -70℃ environmental simulation for composite materials testing, contact LIB industry technical experts to receive a customized selection report, ensuring every mechanical test is efficient, accurate, and safe.

References