This part of ISO 7240 specifies requirements, test methods and performance criteria for point-type smoke detectors that operate using scattered light, transmitted light or ionization, for use in fire detection and alarm systems installed in buildings.For the testing of other types of smoke detectors, or smoke detectors working on different principles, this part of ISO 7240 can be used only for guidance. Smoke detectors with special characteristics, developed for specific risks, are not covered.NOTE Certain types of detector contain radioactive materials. The national requirements for radiation protection differ from country to country and are not specified in this part of ISO 7240.