Chemical sensor

A device that detects a chemical substance and converts its presence or concentration into a measurable signal. Its response can be electrical, optical, thermal, or mechanical.

Chemical recognition: Selective interaction between a chemical species and a sensing material or receptor. Recognition gives a sensor its ability to respond to particular substances.
Analyte: The chemical substance whose presence or amount is determined by an analysis. The analyte is the target chemical a sensor is designed to detect.
Gas detector: A device that detects or measures the presence of gases. Gas detectors apply chemical sensing to hazardous or useful airborne substances.
Physical sensor: A device that measures a physical quantity such as temperature, pressure, or motion. It detects physical conditions rather than chemical identity or concentration.
Transducer: A device that converts one form of energy or signal into another. The transducer turns a recognition event into a measurable output.
Sensing material: A material whose properties change in response to a chemical species. Its chemical response provides the sensor’s recognition or transduction basis.
pH meter: An instrument that measures the acidity or alkalinity of a solution. Its electrode senses hydrogen-ion activity to report solution pH.
Analytical chemistry: The study and practice of determining the composition and amount of matter. Chemical sensors are one tool within the broader field of chemical analysis.
Signal conditioning: Processing that modifies a sensor signal for measurement or interpretation. Amplification and filtering make weak sensor outputs usable.
Molecularly imprinted polymer: A polymer formed around a template molecule, leaving cavities that preferentially bind similar molecules. These synthetic receptors can provide selective recognition without biological components.

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