Accurate and reliable dimensional inspection of parts is crucial
What is Dimensional Inspection?
Dimensional Inspection is the acquisition of measurement data (usually 2D or 3D) of an object. Then those results are typically compared to drawing specifications or CAD models to check whether the measured object is within/outside specified tolerances.
Dimensional inspection can compare what an object actually is to what it is supposed to be, and can accurately measure the objects physical characteristics such as:
- Length, width, and height.
- Angles and perpendicularity.
- Roundness, flatness, and other geometric characteristics.
- Shape profiles.
- Surface characteristics.
- Edge sharpness.
- Thickness and uniformity.
Using Dimensional Inspection in Engineering
Accurate inspection dimensions are critical in engineering. Dimensional Inspections are used to identify and help correct issues which may occur during the manufacturing process. Accurate and reliable dimensional information on parts is crucial to understand the extent of such issues when they arise.
Dimensional Inspection starts with the assumption that the parts to be inspected have been manufactured to the specified design shape, size etc.
Using dimensional inspection during the production process can help prevent costly errors such as:
Flawed batches. A production line that creates duplicate products requires precision setup and alignment. Errors in the production line can lead to entire batches of flawed goods, which can be quite expensive in both time and cost to correct the production error. Dimensional measurement is worth the investment to prevent these expensive mistakes.
Defective parts. Using dimensional inspection as part of the quality control process for high-precision manufacturing ensures that each part meets the required specifications.
Why Is Dimensional Inspection important?
In general, when dimensional measurement is required, the results must be both accurate and precise. Although multiple techniques and countless applications exist, there are four main categories of dimensional inspection.
First Article Inspection. Implementing a manufacturing process requires extreme attention to detail, especially if the process is new or if the equipment has been specially designed. First article inspection is required to ensure that the equipment was properly installed and calibrated, and to verify the manufacturing process. Dimensional measurement is used to compare the first objects from the manufacturing line to 3D CAD models, engineering drawings with tolerances, and/or other specifications.
Quality Control. When objects coming off a manufacturing line must meet certain quality standards, measurement equipment is used to confirm that the dimensions fall within the required tolerance levels. In some cases, when the tolerance levels are more rigorous, each object is measured automatically. In other cases, batches might be spot-checked for quality.
Regulatory Compliance. In industries for which regulatory compliance is necessary, dimensional measurement ensures that the required specifications are met. Regulatory bodies such as the FDA or FAA often have requirements regarding the dimensions of certain components.
High-Precision Engineering. When creating a larger assembly from smaller parts, high precision is often required. If a minor flaw or inconsistency can impact an entire process, ensuring that such imperfections do not exist is critical.