Allen-Bradley 1732ES-IB8XOB8 - Page 155

Rockwell Automation Publication 1791ES-UM001G-EN-P - November 2016 155
Safety Data Appendix B
Table 65 - Calculated Values for Probability of Failure on Demand (PFD), Probability of Failure
per Hour (PFH), and Mean Time To Failure (MTTF)
Cat. No. Proof Test Interval
(Mission Time
(2)
)
PFD PFH
(1/hour)
Spurious
Trip Rate
(STR)
(3)
MTTF
Spurious
(4)
(years)
Year Hour
1791ES-IB8XOBV4
Single Channel Inputs
1 8760 2.81E-05 6.41E-09 5.612E-06 20.33
2 17520 5.61E-05
5 43800 1.40E-04
10 87600 2.81E-04
20 175200 5.61E-04
1791ES-IB8XOBV4
Dual Channel Inputs
1 8760 1.12E-06 2.63E-10
2 17520 2.25E-06
5 43800 5.64E-06
10 87600 1.13E-05
20 175200 2.27E-05
1791ES-IB8XOBV4
Dual Channel Outputs
1 8760 1.38E-06 3.38E-10
2 17520 2.76E-06
5 43800 6.95E-06
10 87600 1.41E-05
20 175200 2.89E-05
1791ES-IB16
Single Channel Inputs
1 8760 2.80E-05 6.40E-09 3.309E-06 34.48
2 17520 5.60E-05
5 43800 1.40E-04
10 87600 2.80E-04
20 175200 5.60E-04
1791ES-IB16
Dual Channel Inputs
1 8760 1.10E-06 2.60E-10
2 17520 2.20E-06
5 43800 5.50E-06
10 87600 1.10E-05
20 175200 2.20E-05
1732ES-IB12XOBV2
Single Channel Inputs
1 8760 2.32E-06 5.38E-10 6.791E-06 16.81
2 17520 4.63E-06
5 43800 1.16E-05
10 87600 2.33E-05
20 175200 4.69E-05
1732ES-IB12XOBV2
Dual Channel Inputs
1 8760 5.51E-07 1.35E-10
2 17520 1.11E-06
5 43800 2.78E-06
10 87600 5.64E-06
20 175200 1.16E-05
1732ES-IB12XOBV2
Dual Channel Outputs
1 8760 5.68E-07 1.43E-10
2 17520 1.14E-06
5 43800 2.87E-06
10 87600 5.81E-06
20 175200 1.19E-05