There are many technical terms that engineers use when referring to reed switches. The next two slides cover some of the most common terms. Ampere Turns measure magnetic field strength used to actuate a reed switch. It is the product of current and the number of turns in a standard electromagnetic coil. Ampere turns are used to compare sensitivities usually in the range of 10-60 AT. Other units of measure include milli-Tesla, Gilberts and Gauss. Operate and Release Values are a measurement of the operating and release points, often in units of AT. Contact Resistance is a measure of the conductivity of a switch and is measured in milli-ohms.