Detector—a device used for determining the presence or passage of vehicles or pedestrians.
Any alarm device that can be connected to a security system to provide notification of an alarm event to the control panel. Door/window contacts, motion detectors, glass break detectors, and smoke detectors are some of the most common detectors found on a security system.
A mechanism for sensing a physical property or characteristic of, or the presence or absence or passage of, the work or the product or a movable element of a machine; which mechanism effects a signal or impulse as a result of such sensing. The signal or impulse is sent through a transmitter, and effects or initiates the functioning of a machine part or assembly controlled by the detector.
A passive IR, visible, UV detector turns photons into an electrical signal. The IFOV of the detector is its solid angular subtense. There is sometimes confusion between the detector subtense (size) and the pixel (picture element size). They are the same for a staring sensor, but in a scanner it depends on the array offset and number of samples per dwell. A pixel area is often only one-sixth or one-eighth of a detector angular area.
A device in a radiometer that senses the presence and intensity of radiation. The incoming radiation is usually modified by filters or other optical components that restrict the radiation to a specific spectral band. The information can either be transmitted immediately or recorded for transmittal at a later time.
Detector has been defined 12 different ways in documents like Manual on Uniform Traffic Control Devices, Security Glossary & Definitions of Terms, USPC Consolidated Glossary, and 7 more.