In summary, Reed Switches are electrical switches that are actuated by a magnetic field. Common terms used to describe the magnetic sensitivity of a Reed Switch include Ampere-turns (AT), Pull-In, and Drop-Out. One critical factor to consider in a sensing application is the orientation of the magnetic field in relation to the Reed Switch contacts. Key selection criteria for Reed Switches include contact form, size, magnetic sensitivity, switching load, and expected lifetime. Reed Switches are well suited for use in a wide range of proximity, level, speed, and flow sensing applications.