A modular test instrument comprises a base unit and one of a selection of application modules, neither being capable of performing end-user functions without the other. When physically assembled to one another, the base unit and application module comprise a structurally unitary device specialized for...http://www.google.com.tw/patents/US20020064255?utm_source=gb-gplus-share專利 US20020064255 - Modular test instrument
