What is Highly Accelerated Life Testing?
Highly Accelerated Life Testing (HALT) stresses a product to find its weaknesses. HALT tests can help you find your product’s weaknesses and improve its reliability and durability. This can improve quality, customer satisfaction, warranty costs, and safety. As product designers, we must meet customer and public expectations for reliability and quality.
As an example, if you are building a ruggedized outdoor camera for a security company, for instance, you would want to guarantee that it can endure harsh temperatures, humidity, and vibration. You would also want to ensure that the camera can resist accidental falls and accidents without being damaged. HALT testing would be excellent for simulating these harsh climatic and operational conditions and identifying any design flaws in the camera.
In this article, we are going to look at how HALT testing can help you as a designer, understand what highly accelerated life testing is when to use it, how to analyze the results, and ultimately how to improve the design and reliability of your product.
Highly Accelerated Life Testing my product, why do I need it and when should I do it?
You can see the graph here shows the different stages of the new product introduction (NPI) process. HALT would generally take place between the PROTO and DVT stages. This will allow the product design to be verified and identify any design weaknesses that can be addressed before moving into the tooling stage.
Highly Accelerated Life Testing (HALT) is a type of product reliability testing that identifies and eliminates potential design flaws and manufacturing faults. It subjects a product to extreme environmental conditions and loads in order to uncover its limitations and vulnerabilities.
The purpose of HALT is to detect a product’s flaws early in the design and development process so that they can be addressed prior to the product’s distribution. HALT tests are often conducted on a single prototype or pre-production unit to validate the product design and establish dependability goals.
Throughout, the product is subjected to a series of increasingly severe stress tests, such as temperature cycling, vibration, shock, and other environmental and mechanical stress elements. The product is then monitored for indicators of failure, and the test results are utilized to identify areas for design and production process improvement.
Risks of NOT doing highly accelerated life testing
The danger of not doing a Highly Accelerated Life Test (HALT) on a newly developed product can be substantial. Without HALT testing, there is a greater chance of product failure, which can result in product recalls, warranty claims, and even safety issues that could injure customers.
Moreover, without HALT testing, it is more challenging to discover and correct design flaws or weaknesses early in the product development cycle. This can result in additional development expenses, product launch delays, and damage to the company’s reputation.
In addition, HALT testing can assist discover any potential manufacturing flaws that may develop when the product is subjected to real-world stressors. By discovering these flaws early, organizations can minimize costly manufacturing mistakes and improve the product’s overall quality.
What are the steps involved with Highly Accelerated Life Testing?
This is an overview of the stages involved in conducting a HALT test. The particular elements of the test, including the circumstances employed, the techniques for monitoring the product, and the interpretation of the data, will vary depending on the product being tested and the goals of the test. Each test should be designed and configured to match the product you are developing and testing, but these steps are consistent:
- Define the test objectives: The first phase of a HALT test is to identify the objectives of the test. This comprises identifying the product or system to be tested, the precise conditions that will be utilized to stress the product, and the objectives of the test, such as locating design flaws or increasing the product’s overall reliability.
- Prepare the test setup: Next, arrange the test setup, which includes the equipment that will be used to stress the product, such as environmental chambers, vibration tables, and shock generators. The test arrangement must be designed to safely and effectively stress the product under the test objectives-defined parameters.
- Perform a functional test: Prior to performing the HALT test, a functional test is performed to check that the product is working correctly and to set a performance baseline.
- Commence the HALT test: Start the HALT test by progressively raising the stress on the product, beginning with light stress and increasing the severity until the product fails or hits its limitations. Temperature, vibration, shock, and humidity can all be used to apply stress.
- Monitor the product: During the HALT test, the product is monitored for any symptoms of failure, such as a change in performance, an abnormal noise level, or physical damage. Real-time data collection and analysis are performed to uncover potential design flaws.
- Analyze the results: After the HALT test is complete, the findings are evaluated to identify any faults detected during the test. This comprises analyzing the data collected during the test, examining the product for failure indicators, and evaluating the product’s overall performance.
- Make improvements: Based on the findings of the HALT test, adjustments can be made to the product’s design in order to solve any flaws or restrictions discovered during the test. This may involve alterations to the product’s materials, manufacturing method, or general design.
- Repeat the test: If enhancements have been made to the product, the HALT test can be repeated to confirm that the modifications have enhanced the product’s reliability and performance.
The image below shows a HALT test profile for temperature step cycling where the product was subjected to cold temperatures in timed incremental steps before the temperature was increased from somewhere around -100 Deg C to +40 Deg C with incremental steps up to 130 Deg C. The duration of this test shows over 6 hours.
(Image source: Desolutions.com)
What are the different tests that can be used in HALT testing?
HALT testing is a process that exposes a product to extreme environmental and mechanical conditions in order to identify its limitations and weaknesses. There are several different tests that are commonly used in HALT testing, including:
Temperature cycling is a type of test that is commonly used in HALT testing to simulate rapid and extreme temperature changes, which can aid in the identification of any temperature-related flaws in the product. This test is intended to speed up the ageing process of the product and identify any issues that may arise as a result of temperature changes.
The product is subjected to rapid and extreme temperature changes between high and low temperatures during temperature cycling testing. The temperature can change quickly, such as every few minutes or seconds, and the temperature change range can be quite large. A temperature cycling test, for example, could involve exposing the product to a low temperature of -40°C and then rapidly raising it to a high temperature of 85°C.
The goal of temperature cycling testing is to identify any flaws or defects in the product’s design or materials that could lead to failure when subjected to rapid and extreme temperature changes in the real world. A product with poor thermal management, for example, may struggle to dissipate heat during temperature cycling, resulting in the failure of the product’s electronic components.
A car battery is a common example of a product that can benefit from temperature cycling testing. Car batteries are subjected to extreme temperatures ranging from extreme cold in the winter to extreme heat in the summer. Temperature cycling the battery during HALT testing identifies and addresses any flaws in the battery’s design or materials before the battery is released to the market.
Vibration testing, which involves subjecting a product to a series of vibration tests to simulate real-world vibration environments and identify any vibration-related weaknesses, is an important part of HALT testing. The product is subjected to various types of vibration during this testing process, including sinusoidal, random, and sine-on-random vibration.
Sinusoidal vibration testing involves exposing the product to a vibration signal with a single frequency and amplitude. This type of testing is frequently used to identify the product’s resonant frequencies and natural modes of vibration.
Random vibration testing, on the other hand, simulates real-world vibration environments with a wide range of frequencies and amplitudes. This type of testing can detect any flaws in the product’s design or materials that could cause it to fail in real-world conditions.
The characteristics of sinusoidal and random vibration testing are combined in sine-on-random vibration testing. The product is subjected to a random vibration signal that is superimposed with a sinusoidal vibration signal in this type of testing. This type of testing can aid in identifying any potential flaws in the product’s design or materials that could cause it to fail in high-vibration environments.
A cell phone is an example of a product that can benefit from vibration testing. Cell phones are subjected to a wide range of vibration frequencies and amplitudes, including those produced by the device as well as those generated by external sources such as transportation and daily use. Vibration testing during HALT testing allows any flaws in the phone’s design or materials to be identified and addressed before the phone is released to the public.
Other tests may also be done, depending on the product and the desired level of analysis, but these are among the most frequently utilized.
Shock testing (also known as drop testing) is a method of subjecting a product to high-intensity, sudden shocks in order to assess its ability to withstand shocks encountered during use or transportation. A shock test machine can be used to deliver a defined acceleration pulse to the product being tested. The shock generator can generate a variety of shocks, including half-sine, sawtooth, and square-wave pulses. The product can also be tested manually by dropping it from a specified height onto a hard surface.
The shock test simulates the mechanical shocks that a product may experience during shipping, handling, and use. Electronic devices, such as smartphones, tablets, and laptop computers, for example, may be subjected to various types of shocks during transportation or use. A failed shock test may indicate that the shock has damaged or disconnected the device’s internal components. This can result in malfunctions, errors, and other problems that jeopardize the product’s dependability and safety.
The results of a shock test can be used to identify product design flaws such as inadequate mounting or shock absorption features. Manufacturers can improve product reliability, durability, and safety by identifying and addressing these flaws. Furthermore, the test can assist manufacturers in ensuring that their products meet industry shock resistance standards and regulations.
Humidity testing is a method of evaluating a product’s ability to function in humid environments by subjecting it to high levels of humidity. Electronic devices, automotive components, and medical equipment are examples of products that are commonly subjected to humidity testing.
The test can be carried out in a humidity chamber, which is designed to regulate the humidity and temperature levels within. The product being tested is placed inside the chamber and exposed to high humidity for a set amount of time. The humidity level is typically set between 85 and 95% relative humidity, which can cause moisture to condense on the product’s surfaces. The product is then tested to see if any damage or malfunctions occurred as a result of the humidity exposure.
Humidity testing can aid in the identification of potential flaws in a product’s design, materials, or manufacturing processes that could cause it to fail in high-humidity environments. When exposed to high humidity levels, electronic devices that are not properly sealed or protected against moisture may experience corrosion, short-circuiting, or other damage. Humidity testing can be used in the automotive industry to evaluate the performance of electrical and electronic components that are exposed to high humidity and temperature levels in the engine compartment or other areas.
Manufacturers can improve a product’s design and materials to ensure reliable performance in high-humidity environments by identifying humidity-related flaws. This can help reduce the risk of product failure, increase customer satisfaction, and improve the overall reliability and durability of the product.
Power cycling is a type of reliability test that assesses a product’s resistance to repeated power cycling. This test involves repeatedly turning the product on and off to simulate real-world usage scenarios and identify any power-related flaws. The test is carried out by subjecting the product to a series of power cycles, typically ranging from hundreds to thousands of cycles, while monitoring its performance and behavior.
Power cycling can assist in the identification of a variety of potential problems in a product related to its power supply and electronic components, such as intermittent connections, component failures, and other issues that can arise as a result of repeated power cycling. Manufacturers can make design improvements to address these weaknesses early in the product development process, resulting in a more reliable and robust product.
A smart thermostat manufacturer, for example, may use power cycling HALT testing to ensure that the device can withstand repeated power cycling without malfunctioning. This testing would entail repeatedly turning the thermostat on and off to simulate real-world use scenarios and identify any problems with its power supply or electronic components. This testing allows the manufacturer to identify and address any power-related flaws, resulting in a more dependable and durable product.
Overload testing is one of the HALT tests that involves stressing a product beyond its rated capacity in order to identify potential flaws. The goal is to understand a product’s operational limits and design robustness by determining how much stress it can withstand before failing. This testing is especially important for products that are expected to perform in harsh or difficult environments, or for products where safety is critical.
For example, if you are designing a new crane, overload testing may be used to determine how much weight the crane can safely lift before failing. You will identify any flaws in the design and make changes to improve the crane’s safety and reliability by subjecting it to loads greater than its rated capacity.
Mechanical loading, electrical loading, and thermal loading are all methods for performing overload testing. Depending on the product being tested and the goals of the test, the test may involve gradually increasing the load or applying a sudden load. The information gathered during overload testing can assist engineers in improving the product’s design, increasing its reliability, and ensuring that it can withstand the stresses that it is likely to encounter during use.
High-pressure testing is a type of environmental testing that assesses a product’s performance and durability under high-pressure conditions. The purpose of this test is to see if the product can withstand pressures that are higher than its intended operating range without damage or failure.
A hydraulic pump used in heavy machinery is one example of a product that may be subjected to high-pressure testing. The pump must be able to maintain a constant pressure and flow rate in order to power the machinery, and failure could have disastrous consequences. High-pressure testing would subject the pump to pressures above its normal operating range in order to ensure that it can withstand the highest possible pressure encountered in the field.
A pressure sensor used in oil and gas drilling operations is another example. Pressure sensors must be able to withstand high-pressure conditions in deep wells, where pressures can reach thousands of pounds per square inch. The sensor would be subjected to high-pressure testing to ensure that it could continue to function accurately and safely in such harsh conditions.
What equipment is used in the HALT testing?
The equipment used for HALT testing can vary according to the type of test being performed, the product being tested, and the level of information required for analyzing the data. The following equipment is frequently utilized in HALT testing:
- Environmental chambers: These chambers are used to control the temperature and humidity during temperature cycling and humidity testing.
- Vibration shakers: These shakers are used to apply controlled vibrations to the product during vibration testing.
- Shock testers: These testers are used to apply sudden, high-impact shocks to the product during shock testing.
- Power supplies: These supplies are used to control the power of the product during power cycling testing.
- Load frames: These frames are used to apply excessive loads and stresses to the product during overload testing.
- Pressure chambers: These chambers are used to control the pressure applied to the product during high-pressure testing.
- Data acquisition systems: These systems are used to collect and analyze data from the product during the HALT test.
Note 👉 We can arrange this test — you can refer to our own testing lab, RSQ-Labs.
Depending on the product and the desired level of analysis, more specialized tools and instruments may be utilized in HALT testing in addition to those listed above. The objective of HALT testing, as we have already stated, is to discover and eradicate flaws in the product’s design and manufacturing process; therefore, the testing equipment must be able to give accurate and trustworthy data to support this objective.
The image below shows a HALT environmental test chamber that is capable of temperature cycling and humidity cycling tests.
(Image source: Thermotron.com)
How long does it take to complete HALT testing?
The timescales for HALT tests can vary greatly depending on the product, the type of test being performed, and the level of detail required in the analysis of the results. Typically, HALT tests can take anywhere from a few hours to several days to complete, although longer tests are not uncommon.
The length of the HALT test depends on several factors, including:
- Product complexity: The more complex the product, the longer the test may take.
- Test environment: Some tests, such as temperature cycling, can take several hours to complete, while others, such as vibration testing, may take several days.
- The number of tests performed: The more tests that are performed, the longer the HALT test will take.
- Analysis of results: The level of detail required in the analysis of the results will also impact the length of the test.
What budget would I expect to complete HALT tests?
The budget for highly accelerated life testing can vary greatly depending on several factors, including:
- Equipment: The type and quality of equipment used in the HALT test can greatly impact the overall budget. High-end equipment can be expensive, but it may be necessary to obtain accurate and reliable data. The best approach is to use a test lab that already has all the appropriate equipment in place.
- Labor: The cost of labor for the HALT test, including the time of the technicians, engineers, and support staff, can also have a significant impact on the budget.
- The number of tests: The number of tests performed during the HALT test can also impact the budget. More tests can result in a higher budget, but they can also provide more detailed data about the product.
- Length of the test: The length of the HALT test, including the time required for setup, data acquisition, and analysis, can also impact the budget. Longer tests can result in a higher budget, but they can also provide more comprehensive data about the product.
The expense for a HALT test might range from a few thousand dollars for a simple test to several tens of thousands of dollars for a full and complex test. The precise budget will depend on the product, the type of test being conducted, and the amount of granularity required for the data analysis.
For more information on how we can help, contact us to discuss your test requirements.
Who would benefit from using highly accelerated life testing?
There are various reasons why someone building a new product would wish to employ HALT:
- By exposing the product to harsh conditions, the designer can uncover potential dependability issues and make adjustments before the product’s release.
- HALT enables designers to quickly identify and address flaws, hence lowering the time required to bring a product to market.
- By identifying and resolving flaws prior to the product’s release, the designer can limit the number of warranty claims and the associated expenses.
- Increased customer happiness: The designer can increase customer satisfaction and lower the risk of customer turnover by ensuring that the product is reliable and performs as expected.
- HALT can provide useful insights into product design and assist designers in making educated decisions about future enhancements.
Examples of products that would benefit from HALT testing:
HALT can be applied to a wide range of products, including electronic devices, mechanical systems, and consumer goods. Some examples of products that would benefit from HALT testing include:
- Aerospace components: HALT is frequently used in the aerospace industry to evaluate the reliability of components and systems under extreme conditions, including high and low temperatures, vibration, and shock.
- Medical devices: In addition to high and low temperatures, humidity, and exposure to disinfectants, medical equipment must be able to function consistently in a wide range of environmental circumstances. HALT can assist manufacturers in validating their designs and ensuring that their products will perform as intended in the field.
- Automotive systems: HALT is used extensively in the automotive industry to test systems under harsh conditions, such as power steering, braking, and suspension. This ensures that the devices will function as intended and increases the safety of drivers and passengers.
- Consumer electronics: HALT can be used to evaluate the dependability of consumer electronics such as smartphones, tablets, and laptops under extreme conditions such as high temperatures, vibration, and drop tests. This ensures that the products will function as intended and increases consumer satisfaction.
- Industrial equipment: HALT can be used to evaluate the dependability of industrial equipment such as turbines, pumps, and compressors under extreme situations such as high and low temperatures, vibration, and shock. This ensures the equipment will work as intended and increases its reliability in industrial situations.
These are just a few examples of the many types of products that would benefit from HALT testing. Understanding the failure modes and points at which a product will fail provides the opportunity for product design improvements resulting in more reliable products. This not only provides customer satisfaction but also improves brand reputation which every company should be striving for.
How can we help with your HALT testing?
In our test laboratory, we have a comprehensive array of cutting-edge technology and skilled technicians. We can arrange HALT testing for a variety of products to help you evaluate the reliability of a new product or ensure that an existing product can endure the rigors of real-world operation.
Our environmental chambers, vibration shakers, shock tests, power supply, load frames, and data-collecting systems allow us to recreate extreme conditions and stress your product to its limits, revealing any design or manufacturing flaws.
Our objective is to assist you to detect and eradicate any possible reliability issues before they become problems, ensuring that your product is prepared to fulfill your consumers’ needs.
Got any questions or concerns about highly accelerated life testing for your product? Let us know, we’ll be happy to give you some friendly advice and let you know how we can support you.
Read more about highly accelerated life testing and other reliability testing…
- Learn more about NPI Processes and Stages
- Life Test To Determine Product Reliability
- HALT Testing (Highly Accelerated Life Test) Glossary
- What is Highly Accelerated Stress Screening (HASS)?
- Design for Reliability Secrets [Podcast]
- Our reliability test labs are equipped with the state of the art reliability test equipment