LVDTs, linear potentiometers, and other rod-and-cylinder position transducers are often too bulky or complicated for some applications. The Series L miniature displacement sensors from Space Age Control (www.spaceagecontrol.com) provide a relatively simple, space-saving alternative. It uses a bearing-mounted drum mated to a sensor assembly that translates linear position data into electrical signals. The 2-oz unit fits into a package 1.5 in. long and 1.7 in. in diameter.

The design eliminates backlash often associated with spring-loaded and clutched mechanisms, and the threaded cable spool ensures cycle-to-cycle repeatability. They are installed using cam locks or optional tube clamps, often in less than a minute. It operates despite 100-g shocks and 15-g vibrations, and in temperatures ranging from -40 to 85°F. Operating lifetimes exceed 5 million shaft revolutions for the analog version and over 50 million shaft revolutions for the digital version.