For some dimensional inspection applications, the best way to obtain measurements is by using a sensor that comes into contact with the object. Contact sensors work best when the object is rigid and not fragile. They are also often used when the surface of the object does not lend itself to light sensors because it is reflective or too dark.3 Types of Dimensional Inspection Contact Sensors
If your application does lend itself to a contact sensor, the three primary options are:- Coordinate measuring machines - Also known as CMMs, these mechanical systems use probes to measure the surface characteristics of an object. The physical measurements are converted by a transducer into electrical signals that are then analyzed by specialized software programs. Basic models provide XYZ readouts, while more advanced technology can work with CAD models and can be fully automated. CMMs are often used for first article inspection or quality control.
- Articulating arms - These are basically portable CMM systems that are not limited to the linear X, Y, and Z axes. Because they can move on multiple axes of rotation, articulating arms are often used when the object has cavities or other geometry that limits the accuracy of a traditional CMM. They are also useful when an object must be measured in the field.
- Form and contour tracers - For small objects or those with very tight tolerances, form and contour tracers use a stylus with continuous contact on the surface to measure features such as edge radii, thread forms, roundness, and cylindricity.
There are several other types of contact sensors, and even more types of equipment within each category. If you're not sure what type of equipment will produce the desired results, it's best to work with an experienced professional. Contact sensors do not work well for dimensional inspection when the object is soft, elastic, or extremely small. In these cases, non-contact sensors are generally the best option.
Q-PLUS Labs is here to help you decide what type of dimensional inspection equipment makes the most sense for your application. To learn more, download our free guide, or contact us today to schedule a consultation.
What type of contact sensor do you think would work best for your dimensional inspection needs?
