Presence and completeness inspection with machine vision

Is a screw missing? Has the seal been fitted? Was the right label applied? Are all the parts of an assembly present?

Presence and completeness checks are among the most common machine vision tasks. A camera system verifies directly in the production process whether defined features are present, correctly positioned or completely assembled.

VISIONTECHNIK helps you select the right camera, optics, lighting and image analysis for your specific inspection task.

Discuss your application

What can a presence check verify?

The task sounds simple at first: present or not present. In practice, however, small differences in color, surface, position or lighting can decide whether an inspection runs reliably.

Typical applications are:

detecting screws, clips and fasteners
checking seals and O-rings
verifying connectors and contacts
detecting labels or stickers
checking bores and machining features
checking an assembly for completeness
counting parts
identifying the correct part variant
checking fill levels or product components
verifying assembly states

It is not only about the camera

For a reliable inspection, the feature you are looking for has to be clearly visible in the image.

A black O-ring on black plastic is a completely different task from a bright screw on a matt metal surface.

Feature size: How big is the smallest feature that has to be detected reliably?
Field of view: Do you need to check a single position or a complete assembly?
Part position: Does the product always lie the same way, or may it be shifted or rotated?
Surface: Glossy, transparent or heavily textured materials place particular demands on the lighting.
Cycle time: How fast do the parts move, and how much time is available for image capture and analysis?

Which technology fits?

For simple inspections with few features, a compact vision sensor or a smart camera may already be enough.

For larger fields of view, small defect features, several cameras or complex image analysis, classic industrial cameras with separate processing come into play.

Typical components are:

smart cameras and vision sensors
area scan cameras
lenses
telecentric lenses for geometrically critical tasks
ring, bar, coaxial or dome lighting
machine vision software

This information helps us specify the system

Example values - the more specific your details, the more precisely we can narrow down the components.

Field of view: 120 × 80 mm
Smallest feature: 0.5 mm
Working distance: approx. 300 mm
Cycle time: 500 ms
Material / surface: matt aluminum

Suitable product groups

We start with the inspection task, not the camera

A high camera resolution alone does not solve a difficult presence check.

It is often the right combination of optics, lighting, working distance and image analysis that decides whether a feature is detected reliably.

Send us a good part, a bad part, images or a short description of your application and we can narrow down the technical constraints and select suitable components.

Request a feasibility check

Frequently asked questions

Can one camera inspect several parts at the same time?

Yes. If resolution and field of view are sufficient, several inspection areas and features can be evaluated within a single image.

Can the correct part variant be verified as well?

Yes. Besides pure presence, shape, color, contour, position or other visual features can be used to tell variants apart.

Do you need AI for this?

Not necessarily. Many reliable presence checks can be solved with classic machine vision methods. AI becomes interesting when the permitted variants vary widely or when features are hard to describe with fixed rules.