The detector is the eye of the chromatographic system. Without a suitable detector that allows you to see what you separated even the best chromatographic separation is useless. The ideal detector would be sensitive, linear, robust and free of noise and should have a tunable selectivity, an equimolar response etc. In this topic you will first read about what these parameters actually represent. Next, a suite of the more popular detectors will be discussed focussing on their operating principles and tricks to improve their performance.