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
All properties44#
- Version
- 1
- Revision
- 1
- Preferred name
- average frequency of a dangerous failure per hour
- Short name
- PFH
- Definition
- average frequency of dangerous failure of a safety-related control system to perform a specified safety function over a given period of time
- Definition source
- IEC 62061:2021, 3.2.29
- 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]".
- Definition class
- 0112/2///62683#ACC077Safety integrity characteristics
- Unit structure
- 1/h
- Drawing reference
- NR3..2.2ES2
- Initial value
- 0112/2///62720#UAA526 UAA526
- Responsible committee
- IEC/TC 121
- Publisher
- IEC
- Published in
- NON_DEPENDENT_P_DET
- Status level
- Standard
- Version release date
- 2025-09-25
- Revision release date
- 2025-09-26
- Version initiation date
- 2025-09-26
- Original definition date
- 2025-09-26
- Change request ID
- C00094
- C017
- C018
- C019
- MDC_P022
- REAL_MEASURE_TYPE
- MDC_P025_1
- PFH