Comprehensive Proof Test 3 - Emerson Rosemount 644 Reference Manual

Reference Manual
00809-0200-4728, Rev RA
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7.7.3 Comprehensive proof test
Conducting the Comprehensive Proof Test, which includes the Partial Proof Test, detects
approximately 96% of transmitter DU failures and approximately 99% of temperature sensor(s)
DU failures, not detected by the 644 safety-certified automatic diagnostics, for a typical overall
assembly coverage of 96%.
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7.7.4

Comprehensive proof test 3

Proof test 3 includes a comprehensive transmitter proof test, along with a partial sensor proof
test. Conducting Proof test 3 detects approximately 96% of transmitter DU failures and
approximately 90% of temperature sensor(s) DU failures, not detected by the 644 safety-certi-
fied automatic diagnostics, for a typical overall assembly coverage of approximately 95%.
Safety Instrumented Systems (SIS) Certification
Using Loop Test, enter the milliampere value representing a low alarm state. This tests
for possible dormant current related failures.
Check the reference meter to verify the mA output corresponds to the entered value.
Use a Field Communicator to view detailed device status to ensure no alarms or
warnings are present in the transmitter.
Check that sensor value(s) are reasonable in comparison to a basic process control
system (BPCS) value.
Restore the loop to full operation. Remove the bypass from the safety PLC or otherwise
restore normal operation.
Document the test results per the plant's requirements.
Bypass the safety PLC or take other appropriate action to avoid a false trip.
Execute the Partial Proof Test.
Perform a minimum two point sensor verification check. If two sensors are used, repeat
for each sensor. If calibration is required for the installation, it may be done in
conjunction with this verification.
Verify the housing temperature value is reasonable.
Restore the loop to full operation. Remove the bypass from the safety PLC or otherwise
restore normal operation.
Document the test results per the plant's requirements.
Section 7: Safety Instrumented Systems (SIS) Certification
April 2015
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