What Are the Different Alignment and Testing Methods in Metrology?

Metrology is indispensable in various fields because it ensures accuracy and precision in processes and products. Manufacturing benefits from metrology the most because measuring experts help keep their production processes compliant and consistent in producing products that meet the required specifications. However, metrology also has a place in all other industries because it is used in quality control and quality assurance, processes that often involve alignment and testing methods in metrology.

What Is Alignment?

Oxford Dictionary defines alignment as an arrangement wherein two or more things are positioned in a straight line. It also describes components that fit perfectly together, like gears that flush against each other in a mechanical system. 

The physical alignment of components allows mechanisms to work effectively and efficiently. If one or more mechanical components are out of alignment, the entire system will stall and potentially get damaged, as misaligned parts will bump into each other when they shouldn’t. The heavy, abrupt impact can cause these parts to break. If they don’t, they can still produce significant friction and heat, both of which can lead to engine breakdown. 

Alignment is also crucial for measuring instruments themselves. If the measuring tools are flawed and aren’t properly calibrated, they’ll give inaccurate measurements that can snowball into a series of errors in the production process. 

Regular alignment and testing are vital for measuring accuracy, production efficiency, and output quality. To help you maintain or improve on these areas, below is a list of simple yet effective alignment and testing methods in metrology

Effective Alignment and Testing Methods in Metrology

Visual Alignment

The most fundamental method of ensuring alignment and testing is through visual inspection. It checks if components are in the correct position without using tools to enhance one’s sight or physically move the parts in question. 

Since this method relies on hand-eye coordination, it’s not precise or scientifically accurate. Therefore, visual alignment is only ideal for everyday applications in industries where ultra-precision isn’t vital, like general woodworking or construction. 

Mechanical Alignment

When performing visual alignment, sometimes you’ll need tools to verify if a component is as straight as you see it to be and to nudge it in the correct position. For example, carpenters will use a level to check if the wood is perfectly horizontal before nailing a long piece of lumber on a stud wall. Mechanical alignment produces more precise and accurate alignment than a mere visual assessment.

Other simple tools that can be used for mechanical alignment are rulers, framing squares, combination squares, miter hooks, and calipers. They are commonly used in woodworking, carpentry, machining, and assembly lines where there’s a need for higher accuracy in measurements and alignment.

Laser Alignment

Laser-aided measuring tools are best for high-precision alignment tests. Laser alignment uses laser light to map spots on the surface of an object. Since the laser travels in a perfect line, you’ll quickly see when something interferes with its path, like an irregular slope or misplaced protrusion. Laser pointers can also be reduced to a sharp point, making them perfect for testing alignment in industries or processes requiring even higher precision levels, such as in electronics manufacturing or automotive designing. 

The best part about using lasers is it’s handy for non-touch alignment tests. For example, you may use laser alignment to verify whether two distant components that are impossible to bring side-by-side are correctly aligned.

Roundness Testing

This alignment testing method ensures that cylindrical parts like bearings and shafts are stable in rotation and haven’t shifted out of alignment due to wear and tear. It is also used to check the accuracy of round components by measuring radial deviations from an ideal circle and checking for inconsistencies along the circumference. 

A roundness testing tool typically uses a rotating table and a physical probe that traces the circumference to generate a roundness profile. It can also generate other data like radial runout measurements. 

Tools for Alignment and Testing Methods 

  1. Coordinate Measuring Machines (CMM)These sophisticated measuring equipment use physical probes that move on three orthogonal axes to measure an object’s physical characteristics along the X, Y, and Z coordinates.
  2. Optical Coordinate Measuring Systems (OCMS) – These are similar to CMMs, but they use cameras and projectors – optical sensors – instead of physical probes to measure an object. An OCMS projects a structured light pattern onto the surface of an object. If the design is deformed or distorted, the camera will capture that image and interpret the data into quantifiable values.
  3. Optical Interferometry – These tools resemble OCMS because they use light and assess how objects interact with light waves. An optical interferometry tool can measure shape, thickness, and surface quality by analyzing interferences in the light waves used on an object. The measurements are then used to confirm alignment among components that aren’t always adjacent to each other but would occasionally come into contact once the machine or mechanisms they belong to start running. 

Test and Verify Alignments With Reliable Metrology Tools and Professionals

Alignment and testing methods in metrology are instrumental in maintaining quality standards in production processes and output. Having the appropriate equipment for testing alignments in machinery and measuring tools is advantageous. However, it’s often more cost-effective to rent the equipment when you need them. 

ATT Metrology Solutions can help you acquire metrology tools for alignment and testing. Moreover, our metrology technicians can help conduct these tests to ensure accurate findings. So, if you need equipment leasing, professional services, or both, get in touch with ATT Metrology Solutions. 

Contact us today.