11
57-651 Eclipse
®
SIL Certified Safety Manual for Enhanced Model 705-51AX-XXX
6.1.4 Proof Test Procedure
A suggested proof test is described below. This test will
detect approximately 94% of possible DU failures in Model
705-51A*-*** version of the Enhanced ECLIPSE Model 705.
Ensure that all necessary installation and site acceptance test
procedures required to achieve safety are followed.
1. Bypass the safety PLC or take other appropriate action to
avoid a false trip.
2. Send a HART command to force a high alarm current out-
put to the transmitter under test, and verify that the analog
current reaches that value.
This tests for power supply problems such as low supply
voltage or increased loop wiring resistance. It also tests for
other possible failures in the current loop circuitry.
3. Send a HART command to force a low alarm current out-
put to the transmitter under test, and verify that the analog
current reaches that value.
This step tests for possible quiescent current related failures.
4. Remove level from the probe. The Status parameter should
say “Dry Probe” and the level reading should be equal to
the value in the “Level Offset” parameter.
5. Perform a two-point calibration check of the transmitter by
applying level to two different points on the probe and
compare the transmitter display readings and the current
level values to known reference measurements.
6. If the calibration check performed in step 5 is correct, the
proof test is complete. Proceed to step 11.
7. If calibration is incorrect, remove the transmitter and probe
from the process. Inspect the probe for buildup or clogging.
Clean the probe if necessary.
Perform a bench calibration check by shorting the probe
(simulating level) at two different points. Measure the levels
from the bottom of the probe to the simulated levels and
compare to the transmitter display and current level readings.
8. If the calibration is off by more than 2%, contact
MAGNETROL Technical Support for assistance.
9. If the calibration is within tolerance, the proof test is com-
plete. Proceed to step 10.
10. Re-install the probe and transmitter.
11. Restore the loop to full operation.
12. Remove the bypass from the safety PLC or otherwise restore
normal operation.
