Why use a test chamber?
The main function of environmental test chambers is to test the behavior of the products and materials we use on a daily basis, or more specifically (Space, Military, etc.) under extreme climatic conditions. Most of them offer “standard” extreme temperature ranges, generally from -70°C to +180°C.
Different types of tests can be performed on this equipment:
- Tests that subject samples to environmental constraints, such as temperature and humidity, are the most common.
- Tests that subject samples to mechanical stress, such as vibration and traction.
Some equipment can also simulate aging, rapid temperature changes, solar radiation, space environmental conditions and corrosion.
Thanks to their precision and reliability, this equipment enables manufacturers to discover potential defects in their products that need to be corrected before production (regulatory standards). The use of test chambers promotes greater innovation, lower costs and greater customer satisfaction.
How does it work?
The operating principle of a test chamber is explained by the two physical parameters the chamber can control: temperature and humidity.
Temperature:
A test chamber is capable of modulating temperature, i.e. heating or cooling its internal compartment, during a test. It can control air velocity, and homogeneity ensures that all sample surfaces are subjected to the same temperature value.
We heat…
The mechanical system for heating a test chamber comprises electrical resistors placed close to the ventilation system. Heated air enters the chamber through the ventilation system.
And we cool!
Through successive compression, condensation, expansion and evaporation of the refrigerant, the unit cools the test chamber uniformly.
Most test chambers have “standard” temperature extremes. This means they generally range from -70°C to 200°C. However, different temperatures can be achieved by means of specific optional systems. Cascade cooling systems, for example, enable very low temperatures to be reached and/or higher cooling rates to be achieved.
Humidity:
To control humidity inside its tank, the test chamber must be able to perform the following two functions consistently:
humidification and dehumidification.
Humidification
The relative humidity (RH) in a test chamber refers to the internal temperature and the amount of water vapor in the air. It generally ranges from 10% to 98%. When humidity levels are low, the chamber uses a built-in humidity generator to inject water vapor into the test volume.
Dehumidification
When humidity levels in the test chamber are high, the moisture in the air traps on the coldest surface of the unit. The chamber’s built-in evaporator dehumidifies the air inside the test compartment.
It is also possible to inject air (or nitrogen) to “dry” the test pieces more quickly, thus avoiding condensation.
What are the different types of test chambers, and what terms are used?
Not all environments can be simulated by the same equipment. There are, however, a number of more or less versatile types of chamber designed to perform specific types of test.
- Types de chambres d’essai :
- Thermal or Thermostatic chamber: designed for very precise temperature testing. No humidity management.
- Climatic chamber: designed for temperature and humidity testing.
- Oven: designed for hot temperature tests at or above ambient temperature.
- Spécificités optionnelles (liste non exhaustive) :
- Rapid Temperature Variation: Temperature cycles with very rapid variation slopes.
- Thermal shock: very rapid thermal changes using a two- or three-chamber system to create thermal stress on the products under test.
- Aging : Faster analysis of sample lifetime
- Corrosion: Simulation of sample exposure to chemical attack accelerated by hot temperatures, acids or salts (salt spray).
- Solar radiation / Light: Simulation of the effect of sunlight via different types of systems.
- Vibration / Traction: Simulation of the various mechanical stresses potentially experienced by the product under real-life conditions: vibration, traction, shocks, etc.
- Thermal vacuum: Simulating spatial environmental conditions
Why calibrate and maintain your test chamber?
The demands placed on the materials used are becoming increasingly stringent in many industries. Test chambers are the answer. Correctly calibrated, they generate reliable results that simulate product performance in its real-life cycle.
- Metrology:
Carried out in accordance with standard FDX15-140, metrology involves the characterization (measurement verification) of various temperature and/or humidity points, using probes carefully placed inside the test compartment. An uncontrolled change in temperature can have a serious impact on the products tested. Performing metrologies on your equipment enables you to check that your test chambers are operating optimally and consistently.
- La maintenance :
Un entretien insuffisant de votre chambre d’essai peut non seulement entraîner des problèmes de durabilité, mais aussi impacter les performances de votre équipement et la qualité de vos produits testés. C’est pourquoi il est recommandé de réaliser vos maintenances dans les intervalles prévues par une entreprise de maintenance spécialisée. Celle-ci veillera au bon fonctionnement du groupe de refroidissement en effectuant, entre autres, les tâches préventives suivantes :- Checking alarms and safety devices
- Electrical analysis of equipment (voltage and current readings, thermostat settings, etc.)
- Check refrigerant circuit(s)
- Leak test and delivery of appropriate Cerfas
- Computer maintenance – Checking humidity operation (equipment with this option)
- General inspection
- Performance control
- Tests
- Edition of an intervention report for each piece of equipment, detailing the actions carried out
Why choose KRYOMATECH for your test chamber?
Making the right choice is never easy.
To choose the right equipment, you need to answer a few questions:
What type of test do I want to perform?
Temperature or humidity test?
What is the nature of my sample?
Size, weight, mass, product/material standards, operating conditions, etc…
This question will help you to determine the volume of tank you need. Please note: chamber performance is calculated and indicated without mass in the test compartment. To take into account mass or dissipation, please contact us.
What temperatures do I want to reach?
Do you need to reach sub-zero and/or very high temperatures?
Do I need my room to generate humidity?
Do I have other specific needs?
Rapid Temperature Change (RTV), Corrosion Testing, Ageing, Vibration, etc…
These indications are essential to help you make your choice. Professional advice is strongly recommended.
We’re here to help – just contact us.
