a standard, model, or pattern. 2. general level or average: Two cars per family is the norm in most suburban communities. 3. Education. a designated standard of average performance of people of a given age, background, etc. a standard based on the past average performance of a given individual.
For example, pressure regulators are used in gas grills to regulate propane, in home heating furnaces to regulate natural gases, in medical and dental equipment to regulate oxygen and anesthesia gases, in pneumatic automation systems to regulate compressed air, in engines to regulate fuel and in fuel cells to regulate hydrogen.
A sensor is a device that detects and responds to some type of input from the physical environment. The specific input could be light, heat, motion, moisture, pressure, or any one of a great number of other environmental phenomena.The output is generally a signal that is converted to human-readable display at the sensor location or transmitted electronically over a network for reading or further processing.he liquid contained expands and contracts in response, causing the level to be higher or lower on the marked gauge, which is human-readable. An oxygen sensor in a car's emission control system detects the gasoline/oxygen ratio, usually through a chemical reaction that generates a voltage.