High-end transducers are available for precision dimensional measurement. These electronic systems can provide incredibly high resolution and accurate readings, but they are also able to transfer data to a data collection device, usually a computer.
Choosing a single master or dual master air gaging system can be difficult. Understanding the similarities and differences--in performance, price and philosophy--can help a user make the best choice for their application.
Choosing a single master air gaging system can be difficult. Understanding the similarities and differences--in performance, price and philosophy--can help a user make the best choice for their application.
In the June 2009 issue, I wrote about how “less” can be “more,” by purchasing lower-grade master rings and discs and using their certified size—their master deviation—to improve the gaging process accuracy. This topic sparked a number of questions and some confusion, primarily because I did not have space to talk about actually applying this technique on the shop floor.
The use of electronic temperature compensation in gaging has become a valuable tool in improving accuracy as well as gage repeatability and reproducibility (GR&R) in harsh manufacturing environments.
Gage calibration is a routine process followed by most users of precision gages. How regular a gage needs to be checked and its performance documented is usually defined step by step in a documentation procedure.
When an engineer includes a surface finish spec on a print, the intent is usually not just to make the part look good. Surface finish affects how a part will fit, wear, reflect light, transmit heat, distribute lubrication and accept coatings. The finish should be determined by the part’s function: A surface should fulfill engineering requirements without producing a higher-quality finish than necessary.
Measuring the diameter of a hole is one of the most common inspection tasks in a production environment. Given the number and types of tolerances for diameters, many different gaging techniques are available to do these checks. From calipers to air gaging and everything in between, there is an appropriate gage for the application.
Calipers, which can be Vernier, dial or digital, are versatile tools for basic length measurement. They can be used on the shop floor, in the inspection room or even in the home by hobbyists.
ANSI and ISO standards include many different parameters for measuring surface finish. While these parameters are useful in many applications to ensure or enhance functionality, Ra, or average roughness, is by far the most common measure of surface finish. It is included in most specs, and it is both a good starting point and a basic benchmark of process consistency.