Emerson 8800A, Руководство по эксплуатации продукта

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Rosemount Model 8800C Vortex Flowmeter
E-2
ELECTRONICS
VERIFICATION
Electronics functionality can be verified via two different
verification methods:
• Flow Simulation Mode
• Using an External Frequency Generator
Both methods require the use of a HART-based Model 275
communicator or AMS. It is not required to disconnect the sensor to
perform the electronics verification since the transmitter is capable of
disconnecting the sensor signal at the input to the electronics. Should
the user choose to physically disconnect the sensor from the electronics,
refer to Replacing the Electronics Housing on page 4-13.
Electronics Verification
Using Flow
Simulation Mode
Electronics verification can be done by utilizing the internal flow
simulation functionary. The Model 8800C is capable of simulating
either a fixed flow rate or a varying flow rate. The amplitude of the
simulated flow signal is based on the minimum required process
density for the given line size and service type. Either type of
simulation (fixed or varying) will effectively disconnect the Model
8800C sensor from the electronics charge amplifier input (see
Figure 4-7) and replace it with the simulated flow signal. There is no
need to select 2 “Sensor Offline.”
Fixed Flow Rate Simulation
The fixed flow simulation signal can be entered in either percent of
range or flow rate in the current engineering units. The resulting flow
rate and/or shedding frequency can be continuously monitored via a
Model 275 HART Communicator or AMS.
Varying Flow
Rate Simulation
The profile of the varying flow simulation signal is a repetitive
triangular waveform as illustrated in Figure E-1. The minimum and
maximum flowrate can be entered in either percent of range or entered
as a flow rate in the current engineering units. The ramp time can be
entered in seconds from a minimum of 0.533 seconds to a maximum of
34951 seconds. The resulting flow rate and/or shedding frequency can
be continuously monitored via a Model 275 HART Communicator
or AMS.
NOTE
To manually disconnect the sensor for precautionary measures, see
Replacing the Electronics Housing on page 4-13 for details.
Figure E-1. Profile of Varying Flow Simulation Signal
HART Comm. 1, 2, 4, 3, 1
HART Comm. 1, 2, 4, 3, 1, 1
HART Comm. 1, 2, 4, 3, 1, 2
Max Flow Rate
Min Flow Rate
Ramp Time
88
0
0
-0
00
0A
0
4
C