Instruction manual

Startup
continued
RFT9739 Field-Mount Transmitter Instruction Manual 57
Output Wiring Startup TroubleshootingBefore You Begin Getting Started Mounting
Power-Supply and
Sensor Wiring
6.4 Flowmeter zeroing
Flowmeter zeroing establishes flowmeter response to zero flow and sets
a baseline for flow measurement.
Zeroing procedure
To zero the transmitter, follow these steps:
1. Prepare the flowmeter for zeroing:
a. Install the sensor according to the sensor instruction manual.
b. Apply power to the transmitter, then allow it to warm up for at least
30 minutes.
c. Ensure the transmitter is in a security mode that allows flowmeter
zeroing (see "Security modes," page 5).
d. Run the process fluid to be measured through the sensor until the
sensor temperature reading approximates the normal process
operating temperature.
e. Ensure that the sensor is completely filled with fluid.
2. Close the shutoff valve downstream from the sensor.
3. Ensure zero flow through the sensor.
CAUTION
Failure to zero the flowmeter at initial startup could
cause the transmitter to produce inaccurate signals.
Zero the flowmeter before putting the flowmeter in
operation.
CAUTION
Flow through the sensor during flowmeter zeroing will
result in an inaccurate zero setting.
Make sure the sensor tubes are completely full and fluid
flow through the sensor is completely stopped during
flowmeter zeroing.