A test lab is a building product manufacturer’s one-stop shop for engineering, manufacturing quality, and performance verification. Whether supporting new product development, regulatory submissions, or customer assurance testing, a test lab must have the right tools to get the job done. Test labs ensure that building products and equipment conform to industry standards and safety requirements. Virtually every product and component used in the industry undergoes extensive testing programs to ensure durability and reliability under real-world conditions. That is where the test lab operations truly excel.
Common Test Equipment Used
Modern test labs are equipped with numerous test machines and devices to ensure quality, accurate, and repeatable test data is produced based on relevant codes and standards. This test equipment is a large investment for an organization, but a necessary one for industry success. [For all images, See PDF or View in Full Issue.]
Universal Test Machines (UTMs)
Universal Test Machines (UTMs) are the backbone for many test labs, as they can be equipped for a wide range of product testing. UTMs are the most common test machines in a test lab due to their ability to complete a variety of different tests, including tensile, compression, bend, and shear testing. UTMs can be tailored to fit many different applications, and fixturing can be purchased or custom-made to fit the specific requirements of the testing profile.
UTMs are very useful for smaller-scale tests, such as building product, component-level, or small assembly testing, but when larger components or systems need to be tested, a custom-built test frame may be the only option. Testing programs involving multiple actuators or complex geometry may require something that cannot be accommodated with a UTM.
Common Transducers
Along with the different types of test frames, different transducers or instruments can be used to produce meaningful data for the test lab. Basic transducers for a typical structural component testing lab include:
- Load Cells: Measures the force or applied load of the desired component. Many times, a load cell converts an electrical signal from strain gauges into force through calibration.
- Displacement Transducers: Tracks the movement of the device or component (usually under load). A string potentiometer is a common displacement transducer that will extend or retract from a spring-loaded spool to measure linear position.
- Strain Gauges: Converts the specimen’s physical deformation or strain from the measurement of electrical resistance of the transducer.
All transducers must remain accurate to provide reliable test data. Each device has a specific certification period, and they must be calibrated at certain time intervals (usually every 1-2 years). The same is true for the UTMs, as the whole system must be calibrated for test results to be reliable.
Common Test Standards
In a test lab aiming to provide detailed test data for building product approvals, the relevant testing standard is the instruction manual or qualification roadmap. Test standards from ASTM, ANSI, ISO, etc., provide the necessary information that the test lab must follow to ensure all products are evaluated in a similar manner for the correct application.
ANSI/TPI 1
ANSI/TPI 1 is the national design standard for metal plate-connected wood truss construction. This standard provides the guidelines for evaluating the lateral resistance, shear, and tensile strength of metal connector plates for wood truss construction. Not only does it provide standards for evaluating connector plate performance, but it also includes the quality control criteria for manufacturing trusses with metal plate connectors, design procedures and considerations, and manufacturing metal connector plates in general.
ICC-ES AC13 and ASTM D7147
Another common acceptance criteria utilized in a structural component test laboratory is ICC-ES AC13 (Acceptance Criteria for Joist Hangers and Similar Devices) in conjunction with ASTM D7147 (Standard Specification for Testing and Establishing Allowable Loads of Joist Hangers). These documents contain the testing protocols for Joist Hangers, but also similar builder products such as post bases, hurricane ties, and framing angles. ICC-ES AC13 and ASTM D7147 also provide the loading protocol, specimen geometry, and even how to establish allowable loads through calculation based on test data.
Minimizing Variance and Ensuring Safety
Sample Building Procedures
In the test lab, consistency and reliability are paramount to performance evaluations. It is in the best interest of the laboratory to develop standardized sample building procedures to minimize variance. This includes creating build sheets that detail dimensions, materials, fastener information, and installation methods. The ability to create custom jigging or alignment fixtures is a great addition to any test lab capability that can decrease sample-to-sample variance. Lastly, detailed documentation is essential for both current and future project success. This includes details such as creating specimen IDs for traceability, storing test information in an organized database, and documenting any abnormalities during sample build and testing.
Test Lab Safety Procedures
A testing environment that frequently conducts destructive tests of materials must have a detailed safety protocol in place. Basic safety procedures include Personal Protective Equipment (PPE) such as safety glasses, safety-toe shoes, and cut-resistant gloves in designated testing areas. Safety procedures during active tests involve marking out/blocking restricted zones and setting up fragmentation shields to protect against unplanned material or test specimen failure. Additionally, testing machines and programs are equipped with many safety features, such as limit switches, emergency stops, and routine maintenance to ensure smooth operation. A proactive approach to safety utilizes risk assessment that will evaluate the operation of each project to identify potential risks and streamline mitigation strategies.
The test lab plays a critical role in engineered product success, regulatory compliance, and satisfying customer requests. Daily operations involve detailed standard reviews, execution of engineered test plans, and the use of advanced testing equipment. Test engineers and lab technicians are skilled in mechanical testing and fixturing but also possess deep knowledge of applicable codes and standards. Through expertise and diligence, the test lab ensures building components remain safe, reliable, and effective.
For additional information, or if you have questions, please contact the MiTek Engineering department.