Volume 10, Number 4 • July/August 2002 • Advanced Technologies

Clamp Measures Applied Force

Mark Nunnelee, group lead of the Facility Operations Branch at NASA Dryden Flight Research Center, has developed a clamp that can measure the clamping force being applied to a sensitive substrate or between two parts being bonded together. Flight Loads Laboratory data has proven the functionality of the force-measuring clamp.

The process for measuring the amount of clamping force applied to any object has a history of being tedious. Older versions were bulky and required external power sources, load sensors and equipment that could make the system unstable. The new force-measuring clamp has many advantages, one of them being its compact size. It can be adapted to almost any size clamp to accurately measure and display almost any magnitude of force being applied. It needs no external equipment and is easy to operate, moving the process from tedious to effortless.

Not only does the force-measuring clamp act as a sensor that detects and measures the amount of force being applied by a clamping tool, but also it serves as a loading mechanism, contains the signal conditioning, contains its own power source and displays the amount of force.

“The strain gauge signal is fed into the data-acquisition circuitry and calibrated to read the desired units. The calibrated signal is then fed into a digital display that the user can read,” says Nunnelee. All of these features are included in one innovative device.

The force-measuring clamp could be applied to numerous practical purposes, from measuring the appropriate force for adhesive curing, to measuring clamping forces while curing composites, or determining the exact pressure exerted by delicate medical equipment.

In the future, Nunnelee would like to see this device become even more compact, with more options for the digital display, special packaging of components and the use of the same technique on other force devices. More extensive testing will take place in the future. Q

For more information, contact Mark Nunnelee at Dryden Flight Research Center, phone: 661/276-2882, mark.nunnelee@dfrc.nasa.gov. Please mention you read about it in Innovation.

NASA Official: Jonathan Root • Web Design: Printing & Design Office, NASA Headquarters • Credits