This document provides information regarding ice detector technology, design and operating requirements. The SAE document AS5498 provides detailed information regarding the requirements, specifications, qualification, and certification of icing detection systems. This document is not meant to replace AS5498 but to enhance it by considering unique aspects of sensing technology and in particular those that may not be certificated at the time of this revision. To that end an effort has been made not to duplicate information contained in AS5498. Icing rate information is included where applicable. The primary application is associated with ice forming on the leading edges of airfoils and inlets while the aircraft is in flight. Information related to detection of ice over cold fuel tanks and icing at low velocity operation is included. The material is primarily applicable to fixed-wing aircraft. Unique requirements for engine inlets and rotorcraft are also provided.