UL-521 › Complete Document History
Standard for Heat Detectors for Fire Protective Signaling Systems
| Complete Current Edition: |
7TH EDITION - HEAT DETECTORS FOR FIRE PROTEC - Feb. 19, 1999
CHANGE 10/02 - CHANGE 10/02 FOR 7TH EDITION - Oct. 3, 2002
CHANGE 10/04 - REVISION CHANGE - CODE A - Oct. 22, 2004
CHANGE 07/05 - REVISION CHANGE - CODE A - July 20, 2005
CHANGE 01/10 - REVISION CHANGE - CODE A - Jan. 29, 2010
CHANGE 05/10 - REVISION CHANGE - CODE A - May 19, 2010
CHANGE 04/15 - REVISION CHANGE - CODE A - April 9, 2015
CHANGE 10/16 - REVISION CHANGE - CODE A - Oct. 12, 2016
CHANGE 12/17 - REVISION CHANGE - CODE A - Dec. 8, 2017
CHANGE 07/19 - REVISION CHANGE - CODE A - July 1, 2019
CHANGE 11/20 - REVISION CHANGE - CODE A - Nov. 18, 2020
CHANGE 03/21 - REVISION CHANGE - CODE A - March 24, 2021
CHANGE 07/22 - REVISION CHANGE - CODE A - July 26, 2022
CHANGE 02/23 - REVISION CHANGE - CODE A - Feb. 28, 2023
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Obsolete Revision Information: |
6TH EDITION - HEAT DETECTORS FOR FIRE PROTEC - Jan. 1, 1993
1988 EDITION - HEAT DETECTORS FOR FIRE PROTEC - Jan. 1, 1988
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