Products and variants
List dimensions, finishes, colours, packaging formats, changeovers and the normal range of acceptable variation.
Machine-vision buyer's checklist
How to specify a vision inspection system
A useful specification defines the quality decision and production conditions before naming cameras or software. Use this guide to prepare a quotation-ready brief.
Application-led design Proved against the real product, defect and production conditions.Direct answer
What should a vision inspection specification contain?
Define the products and variants, visible defects, acceptance limits, smallest critical feature, line speed, product presentation, environment, required response, records, interfaces and test method. Include representative good, failed and borderline samples so suppliers can prove the optical approach before final design.
Typical project scope
What the system can cover
Each requirement is tested against representative products, normal variation, line speed and the agreed production response.
Defects and limits
Describe each fault, smallest critical feature, location, frequency, consequence and measurable pass/fail boundary.
Speed and presentation
State maximum rate, spacing, motion, orientation, conveyor behaviour and any product handling already available.
Environment and access
Document ambient light, cleaning, dust, moisture, vibration, temperature, guarding and maintenance constraints.
Line response
Define reject, divert, stop, alarm, guidance, rework or feedback action plus confirmation and fault behaviour.
Data and acceptance
Specify recipes, users, retained results, interfaces, challenge samples and the conditions for factory and site acceptance.
Engineering factors
What determines a dependable result?
Describe evidence, not brands
Camera resolution and software should follow the smallest feature, field of view, speed and decision—not the other way around.
Separate detection from performance
List what must be detected, then agree how misses, false rejects, uncertainty and uninspectable products will be measured.
Include the complete station
Handling, optics, controls, safety, data, rejection, documentation, training and support can be as important as the camera.
Production outcome
Turn the inspection into line control
The useful result is a repeatable decision that operators can understand and the production line can act on.
- Receive quotations that address the same defined production problem
- Expose missing samples, interfaces and layout constraints earlier
- Agree measurable acceptance criteria before equipment is built
- Reduce changes caused by assumptions about variants, rejects or data
Practical delivery
From requirement to accepted system
Write the decision
For each product, state what must pass, what must fail and what may be uncertain.
Assemble evidence
Collect good, failed, borderline and wrong-variant samples plus line photos or video.
Run feasibility
Prove image contrast, feature resolution and method limits under representative conditions.
Freeze acceptance
Agree scope, interfaces, challenge set, speed tests, faults, documentation and handover.
Decision guidance
Write acceptance criteria in measurable production terms
Avoid phrases such as ‘detect all defects’ or ‘100% accurate’. State the fault class, size or tolerance, product range, line condition and test sample. Then define how many samples will be challenged, what result is required and how false rejects and uncertain cases are treated.
- Include normal product variation, not only perfect good samples.
- Keep separate requirements for detection, reading, verification and formal code grading.
- Define the response to unreadable, missing and incorrect results independently.
- Record assumptions and exclusions so commercial comparisons remain fair.
Related guidance
Continue planning your inspection
Questions, answered
How to specify a vision inspection system FAQs
What samples should be supplied for a vision trial?
Provide representative good products, known failures, borderline examples, every important variant and examples of normal process variation. Label the reason each sample should pass or fail.
How should inspection accuracy be specified?
Tie performance to the defined product range, defect class, feature size, speed and test method. Detection rate, false rejects and uninspectable conditions should be considered separately.
Should the specification name a camera brand?
Only where site standardisation or an existing architecture requires it. Otherwise, define the result, interfaces and constraints so the integrator can select suitable optics and processing.
What should a factory acceptance test include?
Use agreed products and seeded faults at representative speed. Challenge recipes, consecutive failures, tracking, reject confirmation, alarms, bypass control, data and recovery from selected faults.
What information is needed for a budget quotation?
At minimum: product and defect description, dimensions, smallest fault, maximum speed, line photos or drawings, reject requirement, environment, variants and representative images or samples.