1. V. Kozubovsky, Using gas detectors in fire alarm systems. Metrologiya ta prylady, 3(11), p. 26-29 (2008), in Ukrainian. 2. EN 50291: 1999. Electrical apparatus for the detection of carbon monoxide in domestic premises. 3. EN 54-1: 1996. Fire detection and fire alarm systems – Part 1: Introduction. 4. ISO 7240-1: 2005. Fire detection and alarm systems – Part 1: Generalities and definitions.