Untethering Bore Measurement

Introducing wireless data transmission to a gage that is already effective might seem like a simple and straightforward enhancement. However, according to Bob Harman, product manager for the Testar Products Division of Marposs (Auburn Hills, Michigan), wireless transmission through Bluetooth technology can significantly enhance both the economy and versatility of the gage in certain applications.

The company’s “M1 Star” electronic bore gage is now available in a version that features this wireless transmission. One direct benefit is increased reach. While cables connecting the gage to the host computer normally have a maximum length of 5 m, Bluetooth doubles the range to 10 m.

However, the fact that the cable itself is gone may be even more important, Mr. Harman says. An operator inspecting a part such as a transmission component with a series of critical bores will move the gage from bore to bore on each part. Cabling tends to make this gage cumbersome in such an application by restricting motion around the part. In addition, rotating the gage to inspect bore after bore can result in twisting of the cable that may lead to damage and unexpected maintenance costs. The wireless gage, by contrast, can be carried and used freely. The operator can walk any path from bore to bore without having to care for a cable.

That operator could also walk around the setup on a machine tool in the same way. Mr. Harman notes that the combination of wireless technology and this extended range makes it easier to inspect parts right at the machine, particularly large parts that are difficult to move. Doing this is nothing new, because mechanical gages and indicator gages displaying a single reading are inherently “wireless” and therefore just as portable. However, these gages require that the user carefully record readings. The bore gage with Bluetooth permits continuous communication to a computer so that results can be recorded and analyzed without operator attention or possible error. Mr. Harman likens the comparison to the difference between a snapshot and video.

Because the gage uses Bluetooth, the same data could potentially be sent to other wireless devices as well, such as cell phones and PDAs. That is why Mr. Harman says a future generation of wireless gages might be even less encumbered, with the analysis device as easily portable as the gage itself. The only thing currently missing is appropriate measurement software for a hand-held device—a development that isn’t hard to imagine.