A humidity chamber is a tool for testing and analyzing the effect of different variations of humidity on components or products.
The data collected from the tests are then used by the engineers building the product to modify and improve it.
The testing can either be completed under static or a dynamic state, for different varieties of humidity chambers.
How Does A Humidity Chamber Work?
The main components of a humidity chamber/ENVINRONMENTAL CHAMBERS perform two main functions, that is; to allow moisture and heat into the humidity chamber. Moisture can be introduced into the chamber by either spray or bath form, while heat is supplied into the chamber through heating coils or other heating elements.
How Does A Humidity Chamber Work?
Temperature and humidity are two factors that affect the stability of a product.
Manufacturers always have to test how humidity affects their products, as fluctuations in humidity may cause damage to the products
Artificial humidity is created through the following methods: steam generators, atomizers, and water baths
Steam Generators
Steam generators are used to convert water into steam by heating water with immersion heaters within the chamber. The steam then rises to the top of the chamber to create humidity.
A steam generator chamber can produce heat reaching 300°C and up to 1300°C.
Atomizer Test Chambers
Atomizer test chambers are used for generating moisture and humidity, this is possible because it has a spray nozzle that sprays atomized water.
The water is then heated as it passes through the chamber heater to create humidity.
Water Bath Test Chambers
The components of a water bath test chamber include a heating unit, a small stainless steel container, and a control system. This water bath test chamber only requires little water which does not need to reach boiling point.
What Industries Use Humidity Chambers?
Several industries test how different weather conditions can affect the physical, chemical, or mechanical state of their assemblies, products, and so on.
In the past, most products were introduced into the market without properly being tested. Nowadays, manufacturers rely on humidity chambers to test their products under several conditions, then use the data generated to improve the product.
The Industries That Use Humidity Chambers Include The Following:
Automobile
Manufacturers of automobiles use Humidity chambers to determine how their vehicles can fare in certain weather conditions.
This is essential to determine how well vehicles can withstand different weather conditions.
Rubber
Rubber is easily affected by changes in weather conditions like humidity and temperature.
A humidity chamber is used to test how rubber reacts to 95% humidity, this is done to know the melting, and cracking properties of rubber.
Pharmaceutical
Humidity chambers are essential in this industry for testing the stability of drugs when exposed to certain changes in temperature and humidity.
This is to ensure the safety of consumers Of the drugs.
Plastic
When plastic is exposed to humidity or moisture, it may lead to discoloration, chalking, surface crazing, etc.
Plastic manufacturers always test the tolerance level of their plastics against heat and other weather conditions to determine durability levels.
Electronics
Electrical components are exposed to 60% – 85% humidity, to give the manufacturer data on how the products will fare during shipping, storing, and in extreme operational conditions.
Aerospace
Aerospace products/components are tested under harsh conditions considering that aerospace products are normally used in the harshest conditions. One of the popular methods used for testing aerospace products is called thermal cycling. This method involves subjecting materials to dry and wet conditions, in quick succession.
Military
Military hardware, products are tested against rain, extreme heat, wind, and dust. Humidity chambers are used to simulate an extremely moist atmosphere, to generate data about the quality, reliability, and durability of military products.
Medical
Medical products are tested under different conditions to ensure the products meet government and industry-set standards and regulations.
Medical products are also tested to determine whether the product will get contaminated or not, and to also determine its shelf life.
Battery
Battery testing is done to determine the durability of batteries and whether they are prone to corrosion, as well as to determine the overall performance. Batteries are tested in quick succession inside the humidity chamber, so humidity chambers for batteries are built to take over 50 batteries in each testing cycle.
Construction Of Humidity Chambers
A humidity chamber is designed to withstand the various conditions it creates to test the quality of other products, military hardware, and so on.
Every humidity chamber has some similar components like wall design, observation ports, sealing material, doors, temperature settings monitor, and humidity controller.
Parts Of A Humidity Chamber:
Walls
Humidity chambers are double-walled and are either modular or welded to protect the chamber from contamination. Welded walls provide a better seal for the chamber to prevent outside contamination.
Sealing Material
The sealing material of a humidity chamber is built to withstand all sorts of temperature variations, including pressure, compression, etc. This keeps the chamber from getting affected by the products being tested which may damage the chamber or corrupt the test result.
Doors
The doors are double-walled and fitted with heavy hinges to keep the chamber tightly sealed when closed.
Controllers
Humidity chambers have a proportional integral derivative (PID) controller. The controller automatically changes the control function of the chamber to fit the desired performance level.
Temperature
Humidity chambers have heating coils or wires that serve as a direct source of temperature for the chamber. Large chambers have a more sophisticated heating system.
Air Supply
The air supplier circulates humidified air within the chamber, using a fan, circulating wheel, or circulating motor.
Humidity System
One of the ways to produce humidity in a test chamber is by heating water to produce steam. The chambers have vapor control to keep humidity production in check with international standards, it also has an overflow channel to prevent too much moisture retention.
Materials
Most chambers are built with welded steel frames on the outside and stainless steel on the inside. The materials are also treated properly to ensure they are of the highest quality.
What Are The Types Of Humidity Chambers?
There are so many types and designs of chambers. Some chambers are desktop size and suitable for testing small parts, and there are large chambers for testing big products like cars, etc.
The Various Types Include:
Benchtop Humidity Chambers
These are cost-effective small-sized chambers for testing small products or parts, like cellphones, etc. Benchtop chambers sizes range from 0.89 cubic feet to 5.5 cubic feet.
Reach-in Humidity Chambers
Reach-in chambers have a vertical design to allow easy access during use. They come with wheels or casters for extra convenience.
Walk-in Chambers
Walk-in chambers are designed for walk-in, they are mostly used in automobile, battery production. The chambers have sophisticated steam and airflow systems to ensure the proper distribution of steam and air during use.
Drive-in Chambers
This is mainly used in the automobile industry. It allows manufacturers to test their vehicles under various conditions within the chamber.
Scientific Testing Chambers
They are used for testing specimens to determine what needs to be improved about the specimen. Scientific chambers are used in food science, pharmaceuticals, etc.
How To Choose The Right Test Chamber
Factors like space, product size, cost, and so on should be considered before choosing a test chamber
They include:
Space
The test chamber/Temperature Chambers a manufacturer gets must be able to fit perfectly in their available space. Producers of test chambers always work with their clients to ensure they buy a test chamber that fits the client's needs and available space.
Temperature
It is important to know if the chamber can reach the required temperature for your products. Most chambers can reach 200°C, but this may not be enough temperature in certain industries.
Water Supply
Water is needed to create humidity in a test chamber, the size of the chamber determines how much water it uses. The chamber must be connected to an adequate water source and have a reliable drainage system.
Time
It is important to ask about the processing speed of the chamber to know how long it takes to process information and completely collect the data. Chambers with long ramp-up times are not suitable for testing some product types, as delay may taint the generated data.
Relative Humidity
The RH of most humidity chambers is between 20% to 90%. The type of products to be tested and the required data determine how much RH is needed.
Controller
It is important to consider the controller of the chamber before buying one. There are different types of controllers, but the best controllers have microprocessors and are either LED or LCD.
Types
The most common consideration could be whether it's a vertical test chamber or benchtop type. Other factors to consider are how the door opens, if the seams are welded, etc.
Large test chambers are usually built according to the client's request.
What Flaws Does A Humidity Chamber Detect?
A humidity chamber/Temperature Chamber is used to examine items and identify the flaws of the items to allow improvement.
Coatings
A Temp./Humidity chambers is used to test coated products to see how reliable the coatings are.
Fogging
Products like cars that have windows, windshields, etc are tested under rapid temperature and humidity changes to see if the product fogs.
Tightness
Some products are exposed to humidity with different levels of moisture content, to see if they are waterproof, etc.
Mechanical Failures
Mechanical products are tested under various conditions to determine how well they can withstand those conditions.
Standards And Regulations For Humidity Chambers
Several agencies, international, government, etc exist to regulate and control the standards for humidity chambers.
They include:
Institute Of Environmental Science And Technology (IEST)
This agency guides professionals dealing with humidity chambers based on international standards and regulations.
International Organization Of Standardization (ISO)
ISO is an international standard and regulation agency, with representatives/experts from around the world.
ISO standards used in the humidity chamber industry include the following:
ISO 16525-7: 2014 - The standards for testing adhesives.
ISO 10605 - Testing of vehicles to identify electrical faults from humidity testing.
ISO 16428: 2005 - Standards for examining surgical implants.
ISO 7137: 1995 - Standards for testing air space devices.
ISO 9022-20: 2015 - Standards for testing photonics and optics.
Underwriters Laboratory (UL)
UL provides guidelines for the testing and development of new products and existing products to protect against injury, hazard, and risk.
The International Council For Harmonisation Of Technical Requirements For Pharmaceuticals For Human Use (ICH)
ICH is a pharmaceutical products standards and regulations agency for the development, registration, and testing of pharmaceutical products.
Food And Drug Administration (FDA)
The Q1A(R2) of the FDA specifies how the organization treats food and drug testing.
Q1A(R2): the Q1A(R2) contains recommendations on how food, drugs, etc are tested following FDA standards.
ASTM International
ASTM, founded in 1902 is one of the first standard organizations for product testing in sectors like aerospace, medical, etc.
The International Electrotechnical Commission (IEC)
IEC oversees the testing recommendations for the electronics industry and provides standardized methods for carrying testing.
- ●Humidity chambers are for testing how products react in atmospheric conditions.
- ●Testing can be done in a static or dynamic state depending on the product and the required data.
- ●Temp./Humidity chambers are mostly designed according to specific requests from the client.
- ●Industries use humidity chambers to examine how various climate conditions affect the physical, mechanical, and chemical states of components, assemblies, and parts.
- ●Humidity chambers /Temperature Chambers are built and designed to withstand tough conditions.