Environmental Chambers Buying Guide
Environmental Test Chambers-Buying Guide
No new product is deemed market worthy until it passes through environmental test chambers. It is in these chambers new products are tested under various environmental conditions that ensure reliability and quality of the product.
Climate chambers, for this reason, are important for any development process, which makes them necessary for manufacturers. However, environmental chambers are expensive equipment, and many factors need to be contemplated before buying one.
Many factors determine selection criteria, and price primarily determines the purchasing decision for many. This over the time can prove to be a costly mistake.
Therefore, we are discussing important factors that you should consider before buying a chamber. Remember, you get what you pay for; reliability and quality are never determined by price. We will help you to make a decision that will add value to your purchase.
The primary questions that you should ask yourself are:
What will be tested in the chamber?
What should be the capacity of the chamber?
Should it be water-cooled or air-cooled?
What is the range of temperature you need?
There are various types of test chambers; you should decide the type based on the application.
In the following we will discuss different types of chambers, so you can decide what will suit your requirement.
These chambers are relatively huge, big enough to drive vehicles into them. They majorly are either modular or welded. For construction of modular type chambers, pre-fabricated modules or panels are used, lined with urethane foam insulation. The construction limits the temperature and humidity range that can be attained; at maximum, the temperature can reach up to 100 C and 121 C. The humidity range is 70 C and 95% relative humidity (RH).
Alternatively, in welded chambers, as the name suggests, the internal chamber is welded together, which gives it ability to withstand higher humidity ranges and extreme temperature. They are designed to withstand altitude conditions, and because of all these features, they are more expensive than a modular type.
They are the most common type of remote conditioners or chambers. They come in a range of sizes, starting from 0.5 cubic feet to 70 cubic feet. These relatively portable or handy chambers can simulate practically any environment condition, from temperature variations to humidity, to altitude to rain solar to vibration. Specialized thermal shock chambers are also available in different sizes and configurations; they can change temperature condition from one to another a matter of seconds, checking the reliability in adverse conditions.
Primarily, two types of refrigeration systems are available: expanded refrigerant and mechanically cooled.
In refrigerant-based cryogenic chambers, temperatures can go down to –184 C, using liquid nitrogen. Alternatively, carbon dioxide can be used as refrigerant; however, it can only achieve temperature down to –68 C. These gases unlike, chlorofluorocarbon, are environmentally safe and can be vented directly to the atmosphere.
Mechanically cooled systems follow the same principle that are used in home refrigerators. They are further classified as single-stage refrigeration and cascade refrigeration systems. A single-stage refrigeration system can bring down temperature to –34 C, and in some cases, 40 C, whereas cascade refrigeration systems have two separate systems that can cool the chamber down to –85 C. Single-stage refrigeration systems are less expensive and have fewer parts, which makes them more reliable.
When it comes to environmental test chambers, humidity can be confusing. The humidity measure that you will see in the specifications is RH, which is temperature specific. The moisture in the air at 30 C and 50% RH is not equal to 15 C and 50% RH, the capability of air to hold moisture reduces, as the temperature goes down. This complicates the whole functioning. Instead of going into details, if you need to achieve lower humidity levels, ask for a chamber fitted with a dry-air purge system and refrigeration valves.
In most temperature chambers, the common temperature–humidity range is 7 C to 85 C, with 10% to 98% RH, which is limited by a 5 C dew point.
Other than these considerations, you need to know about air-cooled or water-cooled chambers, construction, safety, temperature change rate, and supplier service after the sale. All these will ensure that you get the best chamber for your requirements.
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