PCB Piezotronics IMI Sensors EX640B02 Installation And Operating Manual page 39

O
n
PCB FUNCTIONAL SAFETY SIL SUMMARY AND RESULTS
Summary
This summary report details results of the reliability analysis performed on the PCB Piezotronics 4-20 mA
Output Velocity Sensor and 4-20 mA Output Acceleration Sensor model 64XYZZ Series. These results are
based the following PCB Piezotronics documentation. Design changes from this documentation package
would need to be evaluated for the impact on reliability characteristics.
1. Electrical schematic 23927-B
2.
Electrical schematic 24297-E
3. BOM 21459-01-L
4. BOM 24297-01-209-100-G
5. Manual 640BXX
Reliability calculations were conducted at the component and circuit level using the methodology outlined in
MIL-HDKB-217F. Product level failure parameters were then calculated in accordance the functional safety
approach of lEC 61508-1:2010, IEC 61508-2:2010, JEC 61508-6:2010, and lEC 61508-7:2010.
Results
The results from the FMEA are given below for the 4-20 mA Output Velocity Sensor and 4-20 mA
Output Acceleration Sensor model 64XYZZ:
Name
Circular
Terminal Block
Connector
Architecture
lool
lool
Proof test interval (Annual)
89760 h
PFDavg 1.255x10 3
SFF
86.27%
HFT
0
SIL Capability (Low Demand Mode)
2
SIL Capability (Continuous Demand Mode)
2
Architecture lool
PCB SIL Sensor Rating
Report No: 103685042C51T-001
8,760 h
1.299x10 3
86.12%
0
2
2
lool
2 of 3