Testing q & a

What is testing ?

The quality of a material going into a manufactured product is as important as the reliability of the production process. Materials testing helps us to understand and quantify whether a specific material or treatment is suitable for a particular application.

With the wide variety of materials and treatments available in the marketplace, testing can help narrow down the choices to the most appropriate selection for the intended use. For many industry applications, testing is performed to certify material to a given standard or specification, or to verify that it meets other stringent criteria before it is put into use.

WHY IS TESTING IMPORTANT ?

Materials Testing is performed for a variety of reasons and can provide a wealth of information about the tested materials, prototypes or product samples. The data collected during testing and the final test results can be very useful to engineers, designers, production managers and others.

Here are some of the reasons material testing is important:

Meeting requirements of regulatory agencies
Selecting appropriate materials and treatments for an application
Evaluating product design or improvement specifications
Verifying a production process

At times, governments and regulatory agencies set the standard that firms must meet. Manufacturers are required to follow these standards, which are often specified test procedures, to demonstrate agreement. Many times, a product is utilised in critical applications where a failure could cause damage and injury that could be dangerous, such as manufactured items and parts that play an important role in reactors, and sometimes medical implantation.

Manufacturers can ensure that their goods conform to some international test standards, such as IS, BIS, ISO, ASTM, DIN, and so on, in addition to following a process or procedure to test a material or a product. This is one of the finest techniques to ensure that the material and product are of high quality. Regulatory authorities also require that products be tested in accordance with standards before they can be released to the public.

WHEN SHOULD TESTING BE CONDUCTED ?

Testing is an essential part of both design and manufacturing processes, not only when safety is a concern, but also for any company committed to selling reliable products and minimizing damage and costs if problems do surface. Testing is often performed early on during product development to evaluate a planned production process to avoid potential risks later on. It can also be just as relevant to provide validation for final products on an ongoing basis. Various types of non-destructive testing services are used to evaluate finished products without causing damage to the items.

Testing Service

Salt Atmosphere Testing

Working Principal

The salt spray test chamber operates on a relatively basic premise, namely compressing the corrosive solution into an air spray, spraying the sample, and wrapping the spray around all sides of the sample as much as possible. This test can be run continuously or in cycles until the sample is corroded. The corrosion time is then recorded as the sample’s corrosion resistance. The longer the time, the better the sample’s corrosion resistance.

The corrosion solution in the salt spray test chamber is typically 5% sodium chloride solution or 0.26 grammes copper chloride per litre added to the sodium chloride solution as the salt spray corrosion solution. Furthermore, the salt spray test chamber can separately manage the sedimentation volume and the spray volume of the salt spray to maintain a steady test temperature, simple operation, and a stable test environment. As a result, it is frequently used to assess the corrosion resistance of everyday requirements or industrial equipment.

The test chamber can reach and maintain any temperature in the test working environment, ranging from ambient temperature to 50°C. Conduct salt spray corrosion testing on materials or products in a cabinet of a specific volume while maintaining a constant temperature and relative humidity. This equipment is made of imported corrosion-resistant PVC plastic sheet, which does not react with salt-containing or acidic salt-containing solutions and so does not alter the test findings. The internal and external pressures are balanced in the design of this equipment, and the salt spray can settle freely in the box and be adjusted to the range required by the national standard.

Application

Salt spray testing is popular because it is very cheap, rapid, uniform, and repeatable. Although there is a poor association between the duration of a salt spray test and the projected life of a coating in some coatings, such as hot-dip galvanised steel, this test has gained widespread popularity due to its low cost and speedy findings. Most Salt Spray Chambers today are used to maintain coating operations such as pre-treatment and painting, electroplating, galvanizing, and the like on a comparative basis, rather than to anticipate corrosion resistance of a coating. Pre-treated + painted components, for example, must pass 96 hours of Neutral Salt Spray before being accepted for production. Failure to fulfil this condition indicates instability in the chemical process of the pre-treatment or in the paint quality, both of which must be rectified quickly so that the next batches are of the desired quality. The longer the accelerated corrosion test, the longer the process is out of control, and the greater the loss in non-conforming batches. The primary application of the salt spray test is thus to allow fast comparisons between actual and expected corrosion resistance. The time it takes for oxides to emerge on the samples under test is typically compared to expectations to determine if the test passed or failed. As a result, the salt spray test is most commonly employed in a quality audit function, where it can be used to assess the effectiveness of a manufacturing process, such as the surface coating of a metallic part. Because it does not establish, mimic, or accelerate real-world corrosive conditions, the salt spray test has minimal application in forecasting how materials or surface coatings would resist corrosion in the real world. This is better suited to cyclic corrosion testing.

Testing Standards

IASTM.B117: 2011, IEC 60068-2-11: 2021, ISO 11474: 2014, ISO 9227: 2017 , JIS H 8502: 2018, GB/T 2423.17: 2008, GB/T 10125: 2002, GB/T 5170.8: 2008, GB/T 5170.11: 2008, GB/T 20121: 2006

Temperature Cycle Testing

Working Principal

The chamber is divided into three sections: the pre-cooling zone, the pre-heating zone, and the test zone. The three zones are self-contained. The damper switches the three compartments without moving the test product. When the temperature is normal, the blower introduces the ambient temperature into the test space. When the impact is low, the high temperature and normal temperature dampers are closed, the low temperature tank is connected with the test box, and the pre-stored cooling amount is instantaneously introduced into the test box; at high temperature, low temperature, and normal temperature, the high temperature and normal temperature dampers are closed; The damper is closed, and the high temperature tank interacts with the test box, allowing the pre-stored heat to be rapidly introduced into the test chamber. As a result, the goal of quick temperature change is met.

An air mixing room, a circulation air duct, a heating device and a circulating fan are installed in the high temperature zone, and the high temperature gas is blown out of the air duct through the test area to recover the cycle; the air temperature adjusting room and the circulation are installed in the low temperature zone. There are air ducts, heating and cooling systems, cold storage plates, and circulating fans installed. In the air ducts, air deflectors, dampers, and diffusers are fitted. The cold gas is blown out of the air duct and collected through the test area.

The temperature controller sends a command based on the temperature of the high temperature zone, the temperature of the low temperature zone, and the test temperature as measured by the temperature sensing body in the test chamber, and controls the heater output and the operation of the refrigeration unit via the calculus time and the SSR control module; the sample’s initial temperature can be set. The test requires the selection of a high or low temperature start, the test zone temperature, and high and low temperature impact conditions, as well as high and low temperature zones, to achieve the goal of rapid temperature change and high and low temperature.

The salt spray test chamber works on a simple premise: compress the corrosive solution into an air spray, spray the sample, and wrap the spray as much as possible around all sides of the sample. This test can be performed indefinitely or in cycles until the sample is corroded. The corrosion time is then recorded as the corrosion resistance of the sample. The longer the time, the stronger the corrosion resistance of the sample.

In the salt spray test chamber, the corrosion solution is typically 5% sodium chloride solution or 0.26 grammes copper chloride per litre added to the sodium chloride solution as the salt spray corrosion solution. Furthermore, the salt spray test chamber may regulate the sedimentation volume and the salt spray spray volume individually in order to maintain a constant test temperature, simple operation, and a stable test environment. As a result, it is commonly used to evaluate the corrosion resistance of everyday necessities or industrial equipment.

The test chamber is capable of reaching and maintaining any temperature in the test working environment, ranging from ambient to 50°C. Conduct salt spray corrosion testing on materials or products in a particular volume cabinet while keeping the temperature and relative humidity constant. This apparatus is manufactured of imported corrosion-resistant PVC plastic sheet, which does not react with salt-containing or acidic salt-containing solutions and so does not affect test results. In the design of this equipment, the internal and exterior pressures are balanced, and the salt spray can settle freely in the box and be adjusted to the range required by the national standard.

Application

Thermal shock chambers can be used to test products in the following industries: building materials, automotive, chemicals, wood, electronics, cosmetics, aerospace, plastics, metal, tobacco, pharmaceuticals, textile, packaging industry, bio-tissue engineering, biotechnology, ceramics, veterinary and human medicine, beverage and food, surface technology, microbiology, and insect and plant growth.

Environmental and stability chamber monitors are required in the food, cosmetics, and pharmaceutical industries to ensure compliance with international regulatory organisations’ requirements. Thermal shock chambers can regulate and monitor temperature as well as humidity (for example, mean kinetic temperature). Advanced ageing research in thermal shock chambers help determine the safe shelf-life level and expiration dates.

Thermal shock chambers can be used in microbiology and biology to study the effects of humidity, temperature, and other environmental factors on the growth of algae, plants, insects, viruses, and microscopic animals (such as the Drosophila, popularly known as fruit flies). They enable organ, cell, and tissue culture, as well as insect rearing and plant growth.

Thermal shock chambers are used in the aerospace industry to provide thermal vacuum, thermal tests, and vacuum that simulate outer-space conditions so that space system electronics can withstand high temperature and climate conditions. Thermal shock chambers are used to evaluate portable life support systems for cosmonauts. To test the impacts of lower altitude and pressure conditions, cryogenics equipment, a high pressure oxygen system, and other instruments are employed.

Thermal shock chambers are used in the automotive industry to simulate situations such as direct sunlight and hot roadways. All vehicle manufacturers do these tests, many of which take place in drive-in chambers located within the company’s testing facilities. To check the vehicle’s performance, they simulate real-world situations such as normal humidity levels, air and road temperatures, and severe weather. Drive-in car testing chambers are airtight and can withstand expansion and contraction.

Thermal shock testing, in addition to the complex research protocols used by quarantine bureaus, universities, large manufacturers, and research organizations, ultimately discusses the quality control check of everyday things such as electrical devices, plastics, batteries, paper products, and metals.

Many of the items currently available to consumers are obtained at face value, with little respect for the rigorous testing that they through in order to become commercially available to the end user. This demonstrates the importance of thermal shock chambers in the manufacturing and development of marketable product performance and features. They have played a significant part in advancing technology to current levels while maintaining the dependability and safety of the items we use every day.

Testing Standards

EIA-364-32 Thermal Shock and Temperature Cycling,IEC 60068-2-14 Temperature Testing, MIL-STD 202 Method 107 Thermal Shock Test, MIL-STD 750 Method 1056 Thermal Shock (liquid to liquid), MIL-STD 750 Method 1051 Shock, MIL-STD-883 Method 1011 Thermal Shock Test

Temperature Humidity Testing

Working Principal

The refrigeration cycle employs the reverse Karro cycle, which includes two isothermal and two adiabatic operations. The compressor adiabatically compresses the refrigerant to a higher pressure, and the consumed work causes exhaust as the temperature rises, and then the refrigerant exchanges heat with the surrounding medium isothermally through the condenser to transfer heat to the surrounding medium. The refrigerant temperature decreases when it goes through the shutdown valve adiabatic expansion to produce work. Finally, the refrigerant absorbs heat from the higher temperature object isothermally via the evaporator, lowering the temperature of the cooled object. This cycle is repeated in order to achieve the goal of cooling down. The refrigeration system’s design employs energy adjustment technology, which can not only ensure the normal operation of the refrigeration unit, but also effectively adjust the refrigeration system’s energy consumption and cooling capacity to keep the refrigeration system in the best operating state. Using balance temperature regulation (BTC), the control system controls the output of the heater through the PID automated calculation output according to the predetermined temperature point, achieving dynamic balance even when the refrigeration system is running continuously.

Application

Environmental test chambers for temperature and humidity are used in a variety of sectors to evaluate the performance and durability of materials, products, and components under a variety of temperature and humidity conditions. Following are some instances of how these chambers are used in various industries:

Plastic industry : It can be used to see how temperature and humidity affect plastic materials and products. They can, for example, be used to assess the dimensional stability and strength of plastic components under varying temperature and humidity conditions.

Electronic industry : It is useful for testing the performance and dependability of electronic components and devices under various temperature and humidity conditions. They can be used to test the effects of temperature and humidity on the performance and dependability of circuit boards and other electronic components, for example.

Pharma industry : It can be used in the pharmaceutical sector to test the stability and shelf life of medicinal items under various temperature and humidity conditions. They can be used to imitate pharmaceutical product storage and shipping circumstances in order to assure their purity and effectiveness.

Mobile phone industry : It can be used in the mobile phone business to test the performance and durability of mobile phones and other electronic equipment at various temperatures and humidity levels. They can be used to assess the effect of temperature and humidity on mobile phone performance and dependability, as well as resistance to corrosion and other environmental variables.

Aviation industry : It can be used in the aviation industry to test the performance and dependability of aviation components and systems under varying temperature and humidity conditions. They can be used to imitate the temperature and humidity conditions that aircraft encounter while in flight, as well as during storage and maintenance.

Vehicle industry : It can be used in the automotive sector to test the performance and durability of vehicle components and systems under varying temperatures and humidity levels. They can be used to assess the effects of temperature and humidity on the performance and dependability of automotive components including engines and transmission systems.

Medical instrument industry : Temperature and humidity environmental test chambers are used in the medical instrument industry to test the performance and dependability of medical equipment and devices under varying temperature and humidity conditions. They can be used to imitate the temperature and humidity conditions that medical equipment encounter during storage, usage, and transportation.

Testing Standards

IEC 68-2-1 Environmental testing , IEC 68-2-2 Environmental testing for electrical and electronic products, IEC68-2-3 Environmental testing for electrical and electronic products , IEC 68-2-30 Environmental testing for electrical and electronic products , IEC 68-2-14 Environmental testing for electrical and electronic products, MIL-STD-810D High temperature test, MIL-STD-810D Low temperature test, MIL-STD-810D Damp heat test