kennykkou 发表于 2022-3-7 22:24

UL-521-SUN-Rev-11-18-2020-ED-11-18-2022 改版资料


UL-521-SUN-Rev-11-18-2020-ED-11-18-2022改版资料大纲
Standard: UL 521Standard ID: Heat Detectors for Fire Protective Signaling Systems Previous Standard ID: Heat Detectors for Fire Protective Signaling Systems [UL 521:1999Ed.7+R:01Jul2019

页: [1]
查看完整版本: UL-521-SUN-Rev-11-18-2020-ED-11-18-2022 改版资料