28
RFT9709 Transmitter Instruction Manual
Startup
continued
Zeroing procedure
1. Prepare the flowmeter for zeroing:
a. Install the sensor according to the sensor instruction manual.
b. Apply power to the RFT9709, then allow it to warm up for at least
30 minutes.
c. Ensure the RFT9709 is in a security mode that allows flowmeter
zeroing (see
Security modes
, page 49).
d. Run the process fluid to be measured through the sensor until the
sensor temperature reading approximates the normal process
operating temperature.
2. Close the shutoff valve downstream from the sensor.
3. Make sure the sensor is completely filled with the process fluid under
normal process conditions of temperature, density, pressure, etc., and
ensure zero flow through the sensor.
4. Zero the flowmeter in any of three ways:
• Press and hold the zero button for at least five seconds. Figure 3-1,
page 27, shows the location of the button.
• An external contact closure can be used for zeroing. Close the
contact for at least 5 seconds. (Refer to
External zero switch wiring
,
page 23, for wiring instructions.)
• Issue an auto zero command using a special version of the ProLink
program. The HART Communicator cannot be used for zeroing the
flowmeter. (Contact the factory for additional ProLink information.)
During zeroing, the diagnostic LED remains on continuously. The default
zero time will range from 20 to 90 seconds, depending on the sensor.
After the zeroing procedure has been completed, the LED again blinks
ON once per second to indicate normal operation.
Diagnosing zero failure
If zeroing fails, the LED blinks ON four times per second to indicate an
error condition. An error condition could indicate:
• Flow of fluid during zeroing
• Partially empty flow tubes
• An improperly mounted sensor
To clear a zeroing error, re-zero the flowmeter after correcting the
problem, or abort the procedure by cycling power to the RFT9709.
CAUTION
Flow through the sensor during flowmeter zeroing will
result in an inaccurate zero setting.
Make sure fluid flow through the sensor is completely
stopped during flowmeter zeroing.
09start.fm Page 28 Tuesday, March 2, 1999 9:16 AM
Summary of Contents for Fisher-Rosemount RFT9709
Page 1: ...Model RFT9709 Transmitter Instruction Manual March 1999 ...
Page 2: ......
Page 4: ......
Page 8: ...iv RFT9709 Transmitter Instruction Manual ...
Page 34: ...26 RFT9709 Transmitter Instruction Manual ...
Page 52: ...44 RFT9709 Transmitter Instruction Manual ...
Page 60: ...52 RFT9709 Transmitter Instruction Manual ...
Page 62: ...54 RFT9709 Transmitter Instruction Manual ...
Page 72: ...64 RFT9709 Transmitter Instruction Manual ...
Page 73: ......