Emerson Rosemount 8782 Reference Manual page 121

Reference Manual
00809-0100-8782
5. Connect the transmitter to the Calibration Standard.
6. Power up the transmitter with the Calibration Standard connected.
7. Set the Calibration Standard to the 30 ft/s (9.1 m/s) setting.
8. Wait 30 minutes for accurate flow rate measurement.
9. Read the flow rate.
10. If the reading is within the range, digital trim is not necessary.
11. If the reading is not within this range, use the LOI or other configuration tool to
12. After completing the digital trim, verify the calibration at each flow rate setting on
Reference Manual
See Calibration Standard connections to
The electronics need 30 minutes to warm up and stabilize after the Calibration
Standard is connected, oriented, and situated.
The flow rate reading after warm-up should be between 29.97 (9.1 m/s) and 30.03
ft/s (9.2 m/s).
a) Power down the transmitter.
b) Disconnect the Calibration Standard.
c) Power up the transmitter.
d) Return the transmitter to the original configuration parameters recorded in
Step 2.
e) Return the flow meter into service.
perform a digital trim.
Performing the digital trim means simply executing the Digital Trim function and
waiting for it to complete.
• It takes about 90 seconds to complete. No transmitter adjustments are required.
• You must use a Rosemount 8785 Calibration Standard to complete this
procedure. Attempting a digital trim without a Rosemount 8785 Calibration
Standard may result in an inaccurate transmitter or a "DIGITAL TRIM FAILURE"
message.
the Calibration Standard:
• Use the selector switch on the Calibration Standard to change the flow rate.
• Use the transmitter LOI or other configuration tool to read the flow
measurement.
• The flow rate reading should be within ±0.1% of the simulated flow rate. For
example, at 30 ft/s (9.14 m/s), the reading should be between 29.97 ft/s and
30.03 ft/s (between 9.13 m/s and 9.15 m/s).
• If any of the verified values are not within ±0.1% of the simulated flow rate,
replace the transmitter and/or contact an Emerson Flow representative for
service (see back page).
transmitter.
Maintenance
November 2019
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