What to Look For:
Click on the image to find out more about its various components
Hardware | Video/Optical | Lighting | Software
Benefits of a Field of View System
A field-of-view system affords many advantages for the price and size of the unit.
- Low Cost
- Small Footprint
- Easily Upgradeable
- On Screen Measurements
- Image Capture and E-mail Capabilities
- Data Collection and Report Generation Capabilities
Hardware Design
Choose a stable platform with built in backlight capabilities
Initially you may not have a requirement for through hole measurement, however backlighting can become very useful for illuminating the perimeter of a part with sharp crisp edges.
Consider the Future! Upgradeability of the hardware can be important
Field of view measurements are great as long as you can fit the desired features on the screen all at one time. If you have a need to measure feature to feature dimensions outside of the field of view, a stage with encoders will be required. Look for equipment that can be upgraded in the future to accommodate stage based measurement with the use of a Digital Readout.
Contact the VII for application evaluation!
Video/Optical
A Wide Range of Magnification is Important
Many companies have a wide variety of parts to me measured or inspected. In some cases higher magnification is required however higher magnification provides a smaller field-of-view. This in turn allows the operator to see less of the part at one time.
Instant Evaluation- Tell us about your magnification requirements
Capturing the Optimum Image: Calibration and color correction
Obtaining the best image possible is achieved by technically integrating the best camera, optics, lighting solution, and monitor. However it doesn’t stop there. These components must be color matched and calibrated as a package. All components should be calibrated to true color standards.
Zoom Lenses Provide Flexibility for Magnification and is Easily Upgradeable
A Zoom lens can provide an image which can change magnification easily, is par-focal, and on a manual system can be par-central. Detents (click stops) can be used to for operators to repeat back to predefined magnification positions. Auxiliary lenses can be added to increase or decrease
Not all lenses are created equal: Locate companies that understand the importance of coatings on optics which allow more light to pass into the camera.
Glass by itself is not 100% translucent and there is no such thing as 100% reflectance. With those two principles in mind you can utilize coatings to refract light back into the objectives, keep out diffused light, minimize ghosting that occurs. Coatings applied at a certain wavelength and certain layers allow the "good light (part image)" to go back to the camera and keep the "bad light (reflectivity)" out.
The Relationship between magnification and tolerances must be considered
Most people want to combine the widest field of view with high accuracy measurement. There is a trade off. The higher the magnification the smaller the field-of-view. Based on your tolerances, you must determine if the measurements can be accomplished.
Lighting
Why is the Tungsten/Halogen lighting Solution the Optimum choice for general purpose measurement systems
The Tungsten/Halogen lighting solution gives you more of the color spectrum that the human eye is accustomed to looking at. Most people want to see the image exactly the way it is in real life as opposed to black and white or simple profile.
Lighting can make or break the results of an accurate measurement.
Be sure to work with companies which have the experience to evaluate the best type of lighting for your application and can integrate any and all lighting solutions into their hardware design for turn key solutions.
What are the 3 types of Lighting Generally Used in Video Measurement Systems
- Simple Profile (Bottom Lighting) - Diffused Lighting primarily used for flat parts in which you want outer edges to look sharp and crisp.
- Through the Lens Lighting (Episcopic) - On axis illumination which works well for round parts when looking from the top. The key to on-axis illumination is having something reflective on the bottom. Whether it be the stage glass or a highly reflective surface or something that is of different contrast (example: a dull white card) to increase the contrast level. By combining these 2 features you are getting a true collimated light so it will measure diameters correctly.
- Ring Light - (Oblique) - A general purpose illumination technique which is bringing light in at an angle away from the camera (angle of incidence) to bounce light back up into the camera to image the part.
Lighting is Important - Usually a Ring Light works Great!
With macro applications a fiber optic ringlight can provide shadow-free even illumination over the entire image. In some cases a polarized ring light can reduce reflection on shiny parts. LED lighting can also help features stand out dramatically through the use of strategically positioned light and reflection techniques (See Illumination Section).
Bi-furcated Light Pipes can Provide Lighting into long working distance holes
Some times it is hard to get light down into a bore or long working distance hole. Check for the ability to use the same light source as the ring light or bottom light to look down into blind holes. Since you will generally not be using a ring or bottom light at the same time, you would not need another light source.
Do You Need Bottom Lighting?
Having parts with through holes could benefit through a backlit stage. Be sure to evaluate what kind of backlighting options are available for your requirements. Options may include fluorescent light panels, fiber optic, or LED backlights.
( Learn More - With over 20 years experience with optics and lighting our sponsors have solved thousands of applications requiring a combination of all the lighting scenarios required )
Software
Use Software to help calibrated and maintain magnification options to known standards for repeatable and accurate measurements.
Systems with zoom lenses or variable magnification options must be calibrated to known standards before accurate measurements can take place. Manual Zoom lenses can be configured with repeatable detents (click stops) which allow the operator to change to different magnifications and move back to the same location repeat ably.
Can Edge detection be used on FOV systems?
Yes! Providing the dimensions required fit in the Field-of View, edge detection can provide the ability to remove operator error and increase measurement speed.
On-Screen (FOV) measurement software can increase productivity through measurement tools and image capture capabilities.
One of the advantages of Video Based field-of-view systems is the ability to calculate geometric measurements quickly on the screen, capture the image and paste the dimension or operator comments on the image therefore generating an image based report.
E-mail capabilities allow instant communication between manufacturers, vendors, and customers.
In the past only data reports could be forwarded by mail. Now that a "picture says a thousand words" manufacturers are able to e-mail a full color image report directly from the shop floor or quality lab.