Choosing the Right Measurement Strategy for Modern Manufacturing

Choosing the Right Measurement Strategy for Modern Manufacturing: How Optical, Video and CMM Systems Deliver Accuracy, Repeatability and Throughput

Executive Summary

Manufacturers today face increasing pressure to measure components faster, more accurately and with greater consistency. However, the challenge is rarely a lack of measurement technology, it is selecting the right approach for the application.

Modern metrology is no longer a simple choice between manual inspection and automated systems. Instead, manufacturers must navigate a landscape that includes contact and non-contact measurement, optical and video technologies, and 2D versus full 3D measurement strategies.

Each approach offers distinct advantages and trade-offs. The optimal solution depends on factors such as part material, geometry, tolerance requirements, throughput demands, and the production environment.

This paper provides a practical framework for selecting the right measurement strategy including balancing accuracy, repeatability and throughput while highlighting where optical, video and CMM systems each deliver the greatest value.

1. The Real Challenge: Choosing the Right Measurement Approach

The question is no longer “Which system is best?” but rather:

“Which measurement strategy is best suited to this specific application?”

Different parts – and different industries – demand different approaches:

• A delicate plastic medical component may require non-contact measurement to avoid deformation
• A machined metal part with complex geometry may require tactile probing
• High-volume production may prioritise speed and repeatability over flexibility
• Low-contrast or transparent parts may require optical techniques beyond standard video measurement

There is no one-size-fits-all solution. The most effective strategy is one that aligns the measurement method with the real-world constraints of the part and process.

2. What Really Matters: Accuracy, Repeatability and Throughput

When evaluating measurement systems, three factors consistently drive decision-making:

Accuracy

How close a measurement is to the true value. This is critical for ensuring compliance with tolerances, especially in regulated or high-precision industries.

Repeatability

The ability of a system to produce the same result under the same conditions. This is essential for process consistency and confidence in results.

Reproducibility

The consistency of results across different operators, setups or environments. This becomes increasingly important in production environments.

Throughput

The speed at which parts can be measured. In many manufacturing environments, throughput is just as important as accuracy.

The Trade-Off

In practice, these factors are often in tension:

• Higher accuracy can reduce throughput
• Faster systems may rely on ideal part conditions
• Increased automation can improve repeatability but reduce flexibility

The right measurement strategy balances these factors based on application priorities.

In practice, these factors are often evaluated through Gauge Repeatability and Reproducibility (GR&R) studies. GR&R assesses how much of the measurement variation comes from the measurement system itself, including the equipment, operator and method. When selecting a measurement strategy, it is important to consider not only the theoretical accuracy of a system, but how it will perform in real-world use.

3. Contact and Non-Contact Measurement

Contact Measurement (CMM-based)

Contact systems use a physical probe to measure points on a part’s surface. They are particularly effective for:

• Complex 3D geometries
• Datum-based measurement strategies
• Features that are not optically accessible

Strengths

• Strong for full XYZ measurement
• Reliable for complex forms and internal features
• Established in many quality environments

Limitations

• Physical contact can deform soft or delicate parts
• Slower for high-volume inspection
• Less suited to fast shop-floor workflows (in traditional setups)

The Deltron system below is available for manufacturers in Australia or New Zealand looking for a compact, robust, accurate and repeatable shop floor CMM.

Non-Contact Measurement

Non-contact systems use optical or video-based techniques to capture measurements without touching the part.

Strengths

• No risk of deformation or marking
• Faster measurement cycles
• Ideal for small, delicate or high-volume components
• Easier for operator training and repeatability

Limitations

• Dependent on part visibility and edge definition
• Sensitive to surface finish, reflectivity and contrast
• May require additional techniques for full 3D measurement

Hawker Richardson supplies a number of non-contact measuring systems to manufacturers in Australasia, including the Swift and Hawk from Vision Engineering.  The Hawk is in a class of its own offering users fully automated CNC capabilities.  See the full range of non-contact solutions here.

Key Insight

Contact measurement excels in complex 3D geometry.
Non-contact measurement excels in speed, consistency and delicate parts.

4. Optical and Video Measurement

Within non-contact measurement, the distinction between optical and video systems is critical.

Video Measurement 

Video systems use cameras and edge detection algorithms to measure features.

A key factor in their effectiveness is Video Edge Detection (VED) – the ability of the system to clearly identify and define the edge of a feature using contrast and lighting.

Best suited for:

• High-contrast parts
• Clearly defined edges
• Repetitive 2D measurement tasks
• High-throughput environments

Advantages

• Fast and efficient
• Easy to automate
• Ideal for batch inspection

Limitations

• Performance depends heavily on VED
• Poor edge contrast can reduce accuracy and consistency
• Transparent, reflective or low-contrast parts can be difficult to measure reliably

Optical Measurement

Optical systems rely on advanced optics and lighting techniques, often combined with operator input.

Best suited for:

• Low-contrast parts
• Transparent or reflective materials
• Complex or poorly defined edges

Advantages

• Can resolve features that video systems struggle with
• Effective for transparent plastics and difficult surfaces
• Greater flexibility for challenging applications

Key Insight

Video measurement is typically the fastest option when edges are clear.
Optical measurement becomes essential when parts are difficult to “see.”

5. Understanding X, Y and Z Measurement Needs

A critical factor in system selection is whether the application requires 2D or full 3D measurement.

X and Y (2D Measurement)

Most measurement tasks are fundamentally planar:

• Lengths and widths
• Hole positions
• Profiles and spacing

For these applications:

• Video and optical systems often provide the best combination of speed and ease of use
• Ideal for shop-floor inspection and batch measurement

Z (3D Measurement)

Z-axis measurement becomes essential when dealing with:

• Depth and height
• Step features
• Multi-plane geometry
• Complex 3D components

For these applications:

• Multi-axis non-contact systems or hybrid systems are required
• CMMs remain critical where full 3D geometry is needed

Key Insight

If your requirement is primarily 2D, prioritise speed and simplicity.
If your requirement is truly 3D, prioritise capability and completeness.

6. Measuring Difficult Parts

Some components present unique challenges that strongly influence technology choice.

Transparent and Low-Contrast Materials

• Standard video systems may struggle with edge detection
• Optical systems provide better visibility and definition

Soft or Delicate Parts

• Contact measurement can cause deformation
• Non-contact methods eliminate this risk

Reflective or Complex Surfaces

• Lighting and optics become critical
• Hybrid approaches may be required

7. Industry-Specific Considerations

Different industries prioritise different aspects of measurement:

Medical Devices

• Critical dimensions and traceability
• High repeatability and consistency
• Often small, delicate plastic components

Electronics and Precision Engineering

• Small features and tight tolerances
• High throughput requirements
• Strong reliance on 2D measurement

Plastics and Packaging

• Transparent or low-contrast materials
• Risk of deformation
• High-volume production

Machined Components

• Complex geometry
• Need for full 3D measurement
• Shop-floor robustness

8. Mapping Measurement Strategy to Technology

Different measurement systems align with different needs:

• Video-based systems = high-speed 2D measurement for routine inspection
• Optical/video hybrid systems = flexibility for mixed applications
• Advanced non-contact 3-axis systems = automated measurement with extended capability
• CMM systems = tactile measurement for complex 3D geometry

The most effective environments often combine multiple technologies, selecting the right tool for each task.

9. A Practical Selection Framework

When selecting a measurement strategy, consider:

• Part material – rigid, soft, transparent, reflective
• Feature visibility – clear edges vs low contrast
• Dimensional requirement – 2D vs full 3D
• Tolerance requirements – how tight are they?
• Throughput needs – batch vs high-volume
• Operator skill level – ease of use vs complexity
• Environment – lab vs shop floor
• Risk level – critical components vs general inspection

Conclusion

Modern manufacturing demands more from measurement than ever before. The challenge is not choosing between technologies, but selecting the right combination for the task.

There is no single “best” measurement system – only the best-fit strategy.

By understanding the strengths and limitations of contact and non-contact measurement, and by balancing accuracy, repeatability and throughput, manufacturers can build a measurement approach that delivers both performance and efficiency.

Speak to one of our engineers to see how we can help you optimise your Quality Control with one of our measuring solutions.

Frequently Asked Questions (FAQs)

What is the best measurement system for modern manufacturing?

There is no single best system. The right measurement approach depends on part material, geometry, tolerance requirements, throughput and environment. Many manufacturers use a combination of optical, video and CMM systems.

How do I choose between optical, video and CMM measurement systems?

Use video measurement for high-contrast 2D inspection, optical measurement for low-contrast or transparent parts, and CMM systems for complex 3D geometry.

What factors should I consider when selecting a measurement system?

Consider accuracy, repeatability, part material, feature visibility, dimensional requirements (2D vs 3D), throughput, operator skill and environment.

What is the difference between contact and non-contact measurement?

Contact measurement uses a physical probe, while non-contact measurement uses optical or video methods. Non-contact is faster and better for delicate parts, while contact is stronger for complex 3D geometry.

When should I use non-contact measurement instead of contact measurement?

When parts are delicate, small, require high throughput, or where consistent repeatability with minimal operator influence is needed.

Can contact measurement damage or deform parts?

Yes, especially with soft materials like plastics. This can affect accuracy, making non-contact methods preferable.

What is video edge detection (VED) in measurement systems?

VED describes how clearly a system can detect feature edges using contrast and lighting. Strong VED enables fast and reliable measurement.

Why do video measurement systems struggle with transparent or low-contrast parts?

Because they rely on contrast to detect edges. Transparent or reflective materials reduce edge visibility.

When should I use optical measurement instead of video measurement?

When parts are transparent, low contrast, reflective or difficult for video systems to detect accurately.

What is GR&R in measurement systems?

GR&R (Gauge Repeatability and Reproducibility) measures how much variation comes from the measurement system, including equipment and operators.

Why is GR&R important when choosing a measurement system?

It ensures the system produces consistent, reliable results within tolerance and is suitable for quality control.

When do I need 2D vs full 3D measurement?

Use 2D for planar features and 3D when depth, height or complex geometry is required.

How do you measure transparent plastic components accurately?

Optical measurement systems are best as they can better resolve edges where video systems struggle.

What is the best measurement system for high-volume production?

Video measurement systems are typically best due to speed, automation and ease of use.

Can measurement systems be used on the shop floor?

Yes. Many modern systems are designed for shop-floor use, offering robustness and ease of operation.