Several years ago we were developing a clamp-on photometer, a hand-held instrument that could be clamped onto a communications optical fiber to indicate the presence of light, its direction of travel, ...

(Editor's Note: There are links to the previous parts of this series at the end, below the author's biography.) Determining if one voltage is greater than or less than another voltage is the job for a ...

Synchronous detection is a measurement method where a stimulus is modulated with some frequency and the response is demodulated to bring the signal back down to base band. Performed when a dc stimulus ...