Why Are Testing and Measurement Critical?
Every manufactured part must comply with design tolerances and functional requirements. A single dimensional deviation can lead to assembly errors, loss of functionality, and the risk of mass production waste.Test and measurement processes; not only weed out the faulty part, but also prepare the ground for root cause analysis and continuous improvement by showing where the process has deviated. Therefore, measurement is not the final step in quality assurance but an integral part of production.
Dimensional Measurement Methods
- CMM (Coordinate Measuring Machine): Point-by-point scanning of part geometry and comparison with the CAD model. It is the foundation of high-precision dimensional verification.< / li>
- Optical / 3D Scanning: Visualization of form deviations as a color deviation map through non-contact scanning of the part surface. Ideal for complex surfaces.< / li>
- Profile Projector: Enlarging and measuring the edge profiles of small and delicate parts.< / li>
- Traditional measuring instruments: Quick field inspection with calipers, micrometers, and comparators.< / li>
- Gauges and fixtures: Rapid compliance control with the go/no-go principle in mass production.< / li>
Material and Mechanical Tests
The behavior of the material must be verified as well as the size of the part:- Tensile test: Determination of yield limit, breaking strength and elongation values.< / li>
- Hardness measurement: Material and heat treatment verification using Rockwell, Brinell, and Vickers methods.< / li>
- Impact test (Charpy): Evaluation of material toughness and brittleness.< / li>
- Thickness measurement: Detection of thinning and tearing risk after shaping.< / li>
- Metallographic examination: Microstructure, grain size, and heat-affected zone (HAZ) evaluation through section analysis.< / li>
Non-Destructive Testing (NDT)
Detecting internal and surface defects without damaging the part is indispensable for critical components. Main methods:| Method | Detected Defect |
|---|---|
| Visual inspection (VT) | Surface cracks, porosity, form defects |
| Penetrant test (PT) | Surface-exposed fine cracks |
| Magnetic particle (MT) | Surface and subsurface discontinuities (ferromagnetic materials) |
| Ultrasonic testing (UT) | Internal voids, non-adhesion, thickness deviations |
| Radiographic testing (RT) | Internal porosity and weld discontinuities |
Statistical Process Control (SPC)
Single measurement verifies a single part; statistical control verifies the entire process. Thanks to SPC:- Measurement data are monitored with control charts (control chart)
- Process capability is quantified with the indices Cp and Cpk
- Deviations are detected during the trend phase, before they exceed the tolerance limit
- Measurement system reliability is verified with Gage R&R
- Fire and rework rates are permanently reduced
Measurement Reliability: Calibration and Traceability
The value of a measurement is limited by the accuracy of the device that made it. Periodic calibration of all measuring equipment in a traceable way to national/international standards guarantees the reliability and auditability of the results. It is also a fundamental requirement of ISO 9001 and customer quality requirements.Conclusion
Testing and measurement is an engineering process that produces numerical proof of quality, in which the right device, the right method and the right interpretation work as a whole. The combined use of dimensional measurement, material tests, nondestructive testing and statistical control guarantees the reliability of both the individual part and the mass production.As Avci Mold, we provide confidence to our customers by documenting that every mold and part we produce meets the design requirements completely with our measurement and control infrastructure.