PFHv1rev 12025-09-26IEC 62061:2021, 3.2.29
average frequency of a dangerous failure per hour
0112/2///62683#ACE052
average frequency of dangerous failure of a safety-related control system to perform a specified safety function over a given period of time
- Used by classes
- 1
- Code
ACE052- Data type
- REAL_MEASURE_TYPEmeasure
- Unit
- UAA526 UAA526
Version history1#
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Metadata#
- Note
- Note 1 to entry: Both terms PFH and PFHD correspond to the probability of dangerous failures per hour. Note 2 to entry: The term “average probability of dangerous failure per hour” is not used in this edition anymore but the acronym PFH has been retained but when it is used it means “average frequency of dangerous failure [h]".
- Source document
- IEC 62061:2021, 3.2.29
- Version
- 1
- Revision
- 1
- Status
- Standard
- Publisher
- IEC
- Responsible committee
- IEC/TC 121
- Change request
C00094- Dates
- Original: 2025-09-26
- Current version: 2025-09-26
- Current revision: 2025-09-26