ionization-type detector

ionization-type detector

A type of fire detector that uses a radioactive source to develop a current across an air gap within the detector; when products of combustion enter the detector, they alter the flow of current and activate an alarm; particularly useful where early-warning detection is essential either because of special safety requirements or because protection is required for property of high value.
McGraw-Hill Dictionary of Architecture and Construction. Copyright © 2003 by McGraw-Hill Companies, Inc.