Environmental test

Energy saving control of constant temperature and humidity chamber   In this paper, we make a detailed analysis of temperature and humidity chamber’s hot and cold offset problems, put forward an elimination of hot and cold offset design principles. On the use of multi-body variable refrigerant flow system, proposed a system partition approach, this air-conditioning chassis group is often running, naturally, energy consumption will be more.   Therefore, to control the energy consumption of constant temperature and humidity chamber refrigeration system is the primary component of reducing the energy consumption. The energy-saving thinking and design of the temperature equipment refrigeration system is the most important problem that the engineering and technical personnel need to face. It is a requirement of the room temperature and humidity invariability. Sometimes the temperature deviation requirements within 1 degree Celsius, what’s more, also have higher humidity requirements.   With the rapid development in mechanical processing technology, requiring the deviation scope of temperature and humidity smaller, that means higher demand for the refrigeration system of constant temperature and humidity test chamber, will greatly improve the energy consumption of the refrigeration system. In order to reduce energy consumption, it is necessary to carry out the energy-saving design of the refrigeration system and experiment with it. In addition, because the refrigeration system approach uses traditional units, the current efficient variable refrigerant flow centralized air conditioning system is rarely used. Then the equipment of the cold and heat source costs can also be reduced to complete energy conservation.

The Significance of Making Environment TestIndustries which use environmental testing include automotive, engineering, construction, medical, pharmaceutical, food processing, packaging, and consumer. Everyday products such as car parts, cigarettes, make-up, medicines and kitchen appliances undergo testing by manufacturers to ensure their durability and effectiveness in certain environmental conditions.  An important reason for the process of environmental testing is that it finds flaws and weaknesses in product design and lifespan before it reaches the public market. These findings allow for production adjustments and result in a better quality product arriving on the market.  Once a product is tested and approved in extreme circumstances, there will be lower warranty claim expenses from replacement and repair, and this saves manufacturer expenditure.  Without testing products in a variety of environmental conditions, it is a high risk for a manufacturer to sell the products under warranty. Customers are increasingly demanding longer warranties on products and goods, and it is imperative that a manufacturer has tested the product that he or she is guaranteeing to avoid high reimbursement costs.  Testing can take many hours and can be a costly procedure depending on the size and process undertaken, and yet it is a wise manufacturing choice to undergo environmental testing, especially in terms of long-term expenditure and future benefit.

Temperature Chambers and Environmental Test ChambersThe best way to understand how a product or material will perform in the field or over time is to use a laboratory test chamber to model those conditions. This is done in one of two ways: the test chamber may model the conditions exactly as they are, or the chamber may accelerate aging of the material, subjecting it to years worth of stress in hours or days. Many of these tests are associated with high-stakes applications, where millions of dollars of equipment, or even lives, are on the line. Some test chamber applications must comply with rigorous governmental regulations, such as FDA guideline 21 CFR part 11. This means, that the materials, components, and technologies used in constructing these chambers must be tougher than anything put inside of them, and that the chamber must meet very high performance standards.Some of the most extreme laboratory test chambers are used by NASA to test equipment for space flight and exploration. Components intended for the Hubble space telescope or the International Space Station undergo simulated space conditions in NASA's large test chambers at the NASA Goddard Space Center in Maryland. This testing includes a centrifuge, a thermal vacuum chamber for extreme hot or cold conditions, and an acoustic chamber capable of noise up to 150 db.Compared to these NASA super chambers, most laboratory and industrial test chamber needs are modest. There is no one test chamber that can meet every need, but a wide variety of single-variable and combination environmental test chambers are available to simulate almost any set of conditions you could imagine. Chambers can be as large as a garage, but more often are proportioned to fit in the corner of a laboratory or on a bench top. Many types of test chambers are available, depending on the application and needs. Temperature chambers offer adjustable temperatures only. Other chambers, usually called stability or humidity chambers, offer a range of humidity conditions. Climate chambers simulate conditions of temperature and humidity, and environmental chambers include additional variables, such as light, motion, or dust.Temperature ChambersA temperature chamber is the most basic of laboratory test chambers. A variety of technologies and hardware are available in a temperature test chamber. The temperature may be modulated by electric coils, gravity convection, fan-driven convection, or a circulating water bath. One distinguishing feature of a temperature chamber is the broad temperature range available: some models go as low as -80°C, while the maximum temperatures can be 300°C or higher. Precision and accuracy in temperature settings is important. The actual temperature inside the oven should match as closely as possible the desired temperature, and most ovens are precise to within a few tenths of a degree. As well, evenness of temperature is a major issue in a temperature chamber; there should be no hot or cold spots within the chamber. For this reason, most temperature test chambers include a system for circulating air.Another important feature in a temperature test chamber is the temperature change rate. It is sometimes desirable to test an item at a number of different temperatures. The amount of time spent moving from one temperature to another represents some degree of uncertainty in the experimental results. Rapid temperature change rates can minimize this uncertainty. Alternatively, temperature chambers with programmable change rates give users the ability to design gradient experiments.Humidity ChambersHumidity chambers (also called stability chambers) are most in-demand in industries that package, store, and transport products that are sensitive to moisture, such as the pharmaceutical industry or food packaging. A humidity test chamber will offer a temperature control, but the range reflects what would be found in a normal indoor or outdoor environment—from around 0°C to 100°C. Relative humidity within the chamber can be as low as 10% or as high as 98%. All of the components of the stability chamber must be made of a corrosion resistant material such as stainless steel. A humidity sensor on the inside is an added feature that can improve the accuracy of the device.Temperature Humidity ChambersTemperature humidity chambers (also known as climate test chambers) combine temperature and humidity controls for more rigorous testing conditions. With an extended temperature range similar to a temperature chamber (above) in addition to a humidity control system, the temperature humidity chamber is a specialized piece of equipment for advanced applications. Climate chambers are used extensively in testing semiconductors, where a small amount of corrosion can cause a major failure of an electronic device. This is especially true with electronics that are exposed to outdoor weather conditions, such as military equipment, telecommunications equipment, or photovoltaic solar panels.Environmental Test ChambersIn addition to temperature and humidity, many other aspects of an environment can be modeled and simulated using an environmental test chamber. Environmental chambers that include a pressure control can model low or high altitude conditions, or deep-sea environments. Some test chambers incorporate environmental elements such as light, dust, rain, or motion. An environmental chamber may vibrate, rotate, or shock its contents to mimic rough handling in the field. Light and wind are other stressors that can be incorporated into the chamber.Laboratory test chambers have applications across a wide range of science and engineering disciplines. Industrial uses for test chambers include product stability testing, accelerated aging, shelf life, and test-to-failure. Research uses for test chambers include everything from incubations of delicate biological experiments to simulating extreme conditions on Earth or even in outer space. The choice of a laboratory test chamber is an important decision, because it will be one of the most used (and abused) pieces of equipment in the lab.

Environmental Test Chamber Installation Required Utilities All models will require electrical power and to be placed in an area that is able to handle the load of the chamber or shaker. Depending on the chamber, it may require compressed air, cooling water for the condenser, and purified water for the humidity system. Your Thermotron Application Engineer will be happy to assist you with the specific requirements. Heat Load Be sure the new location is able to handle the heat dissipation from the chambers. If the chamber is air-cooled it will dissipate between 12,000 and 15,000 BTUs per hour multiplied by the high stage compressor horsepower into the room. Example: an air-cooled SE-300 -3-3 will dissipate approximately 36,000 BTUs per hour into the room. If the same chamber was water-cooled it will dissipate 200 BTUs per hour multiplied by the total horsepower into the room, or 1,200 BTUs. Service Access Allow 30-inches of space on all sides of chambers and associated equipment for servicing.  Chamber Placement Air cooled chambers require a high volume of air flow and should be placed no closer than 3 inches from a wall or other obstructions. It is also very important that chambers are not placed in a manner in which the warm air exiting the condenser is drawn into the chamber. This will cause high refrigeration system pressures and test profile shut downs. Remote Refrigeration or Remote Air-Cooled Condenser If the chamber has a remote refrigeration section or remote air-cooled condenser, determine where these components will be located. Is there unobstructed space for interconnect routing? Routing of refrigeration and electrical interconnect above drop ceilings and through an obstructed area increases installation costs and decreases efficiency. Try to locate the equipment in an area with open access for interconnecting the components. Panel Walk-In Chambers Floor quality is very important when installing a panel Walk-In Chamber. The floor must be level to a standard of 1/8” per 10 feet or better in any direction. If the floor the chamber is to be built on has high and low points it will not properly support the chamber structure. It also makes it very difficult to assemble to structure squarely. This creates problems with the structure remaining sealed properly and will reduce the life of the panels.

Types of environmental testsTypes of Process/TestPurposePerformed onAttempts to simulate service environmentElement DevelopmentEarly verification that components,materials and concepts will meet specifications.Samples and prototypesYesDesign VerificationsVerify that systems will meet design specificationsAs close to production configuration as possibleYesReliability DevelopmentFind and eliminate design and process items that reduce reliablityAs close to production configuration as possibleNO (But sometimes misguidedly tries)Environmental Stress Screening Transform latent failures into patent failures before delivery to the end userProduction hardware NOClimatics is the science of measuring,analyzing,controlling and testing with climatic,weather,or meteorological  conditions.Although they are usually thought of as being natural environments,they are often created or modified by man.Climatics deals with variables of temperature,pressure,moisture,corrosive environments,sand&dust,icing,solar radiation,and combinations.