Lock-in amplifier

{
  "id": "MLC-T-CHM-006745",
  "term": "Lock-in amplifier",
  "field": "Chemistry",
  "definition": "An instrument that can extract a small signal with a known carrier frequency from an extremely noisy environment. It functions as a phase-sensitive detector by multiplying the input signal with a reference signal of the same frequency and then integrating the product over a specified time. The output is a direct current voltage proportional to the amplitude of the signal component that is in phase with the reference.",
  "subject": "Analytical Chemistry",
  "see_also": [
    "spectral bandwidth"
  ],
  "references": [
    "PAC, 2021, 93, 647. 'Glossary of methods and terms used in analytical spectroscopy (IUPAC Recommendations 2019)' on page 666 (https://doi.org/10.1515/pac-2019-0203)"
  ],
  "url": "https://mlchart.com/terminology/chemistry/lock-in-amplifier/"
}