UL 521
What is the laboratory for UL 521?
For UL 521, laboratory is FM Approvals; standard title is Heat Detectors for Fire Protective Signaling Systems, verified against its source on 2026-09-17.
UL 521 | Heat Detectors for Fire Protective Signaling Systems |
— osha.gov, retrieved 2026-08-10
- Laboratory
- FM Approvals
- Standard number
- UL 521 verified
- Standard title
- Heat Detectors for Fire Protective Signaling Systems verified
Source
- osha.govhttps://www.osha.gov/nationally-recognized-testing-laboratory-program/fm