Reed sensors are mostly used to detect movement, proximity, and liquid levels. These sensors contain a pair of contacts fixed on ferrous metal reeds, enclosed in hermetically sealed glass, and are often paired with a magnet. The contacts open and close in the presence of the magnetic field, and reveal the various positions and movements. These sensors find use in telecommunications, door contacts, position displays in lifts, alarm system contacts and several other applications. Hall Effect sensors are also based on a magnetic field, with the sensor varying the output voltage depending on the applied magnetic field. The sensor converts the variations into an electrical signal and returns a voltage. These sensors find use in determining wheel and shaft speeds, positioning objects, for proximity switching and for current sensing applications. They also find use in industrial and consumer equipment. A common use is in computer printers, to detect open covers and missing paper. In such use-cases, the hall sensor comes equipped with threshold detection capabilities. Both of these sensors are available in various types, suiting different applications. Effective installation may, however, require accessories such as mounting adapters. Apart from evaluating whether the technical specifications match the requirements, consider the safety and environmental standards of the device as well.