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57-642 ECLIPSE Model 705 Guided Wave Radar Transmitter for Hygienic Industries
9.2
Procedure to Verify Calibration of ECLIPSE
A probe is required for a test bench that is as long as the
longest probe installed in the field. The probe must be of
the same type as in the field.
9.2.1 Initial Baseline Verification of ECLIPSE
The probe and transmitter are calibrated on the actual vessel
in the field. This is normally done by metering in specific
volumes or mass of WFI water through a precision mass
flow meter and “strapping” the transmitter and probe to
that metered quantity. For example, assume that the probe
and transmitter is successfully calibrated in the field to 0 to
100% equals 4 to 20 mA equals 0 to 90 cm equals 0 to 500
liters.
Immediately after that wet calibration, dismount the elec-
tronics from the probe, leave the probe in the vessel and
install the transmitter electronics on the test bench probe.
Note: For any Calibration Verification, changes to the transmitter
configurations (sensitivity for example) are NOT permitted!
Begin by positioning the target at specific positions on the
bench probe as determined by predetermined marks on the
probe or as measured by a laser. Write down the output as
displayed on the transmitter. The target is then moved to
the second mark or position on the test rod as measured by
a laser and the reading on the transmitter is noted. This
procedure is continued for the length of the rod. When the
final point on the test rod is measured and documented, the
electronics can be removed from the test bench and mount-
ed back on the original vessel in the field.
9.2.2 Subsequent Calibration Verification
Periodic calibration verification is required per
21CFR211.68(a). Each licensed facility will have a frequen-
cy of calibration verification documented in their SOPs.
For subsequent calibration verifications, the transmitter is
removed from the probe and the probe remains in the vessel
to prevent breach of vessel sterility. The transmitter is then
placed on the dry calibration verification bench probe. The
Initial Calibration Verification Document is retrieved for
comparison. The target is paced at the first mark, as docu-
mented on the Initial Calibration Verification sheet and the
transmitter reading is taken and written down on the sheet
next to the appropriate level mark. This procedure is com-
pleted for each initial level mark. The results for initial vers-
es “today” are compared. If the accuracies are within the
