81
Reference Manual
00809-0100-4728, Rev MB
Safety Instrumented Systems (SIS) Certification
July 2016
Safety Instrumented Systems (SIS) Certification
5. Restore the loop to full operation. Remove the bypass from the safety PLC or otherwise restore
normal operation.
6. Document the test results per the plant’s requirements.
Table 7-1. Proof Test Intervals
Proof test intervals are based on sensor failure rates from the “
Electrical and Mechanical Component
Reliability Handbook, Second Edition”, exida, 2008
. A low stress environment is assumed, with 30 percent
of SIL 2 PFDavg limit budgeted for the transmitter and sensor element. See the FMEDA report for
additional details or references.
Visual inspection
Not required
Special tools
Not required
Product repair
The Rosemount 644 is repairable by replacement only.
All failures detected by the transmitter diagnostics or by the proof-test must be reported. Feedback can
be submitted electronically at www.EmersonProcess.com/Rosemount/Safety/Safety-Cert-Temp.htm
(
Contact Us
button).
7.8
Specifications
The Rosemount 644 must be operated in accordance to the functional and performance specifications
provided in the Rosemount 3051 Product Data Sheet (document number 00813-0100-4728).
7.8.1
Failure rate data
The FMEDA report includes failure rates and common cause Beta factor estimates.
The report is available at www.EmersonProcess.com/Rosemount/Safety-Products.
7.8.2
Failure values
Safety accuracy: ±2.0 percent
Transmitter response time: 1.5 second
Self-diagnostics Test: At least once every 60 minutes
Sensors
Abbreviated proof test
Extended proof test
4-wire RTD
10 years
10 years
Thermocouple
1 year
10 years
2 years
2 years
Dual Thermocouple
10 years
10 years
Dual 3-wire RTD
10 years
10 years
Thermocouple and 3-wire RTD
10 years
10 years
Summary of Contents for Rosemount 644 HART
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Page 16: ...6 Reference Manual 00809 0100 4728 Rev MB Introduction July 2016 Introduction ...
Page 86: ...76 Reference Manual 00809 0100 4728 Rev MB Troubleshooting July 2016 Troubleshooting ...
Page 138: ...128 Reference Manual 00809 0100 4728 Rev MB Index July 2016 Index ...
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