Emerson Rosemount MultiVariable 3051SMV, Справочное руководство

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10
Reference Manual
00809-0100-4853, Rev AB
Configuration
January 2017
Configuration
2.4 Variable configuration
2.4.1 Units configuration
Units for transmitter variables are configured in the XD Scale parameter in each AI Block. Each AI Block is
connected to a transmitter variable according to the Channel parameter in the AI Block. When the units
in an AI Block are changed, the units of the connected channel variable will be changed in the Sensor
Transducer Block or the Mass Flow Transducer Block accordingly. If multiple AI Blocks are set to the same
channel, the XD Scale units must be manually synchronized to resolve configuration errors.
2.4.2 Mass flow
The following configuration items are found in the Mass Flow Transducer Block.
Note
These configuration items only apply to the Fully Compensated Mass Flow transmitter.
Low flow cutoff
If the measured differential pressure value is less than the low flow cutoff value, the transmitter will
calculate the flow rate value as zero.
The unit for this value is always inH
2
O at 68 °F.
Process temperature mode
The mass flow calculation can use a live process temperature reading or a fixed value based on the
selected process temperature mode. To configure it, select
Actions > Methods > Methods > Mass Flow PT
Mode Setup and follow the on-screen prompts.
Note
The unit for the fixed process temperature value always matches the process temperature primary value
unit. To change this unit setting, see
Units configuration .
Mode Description
Normal
The transmitter will only use the actual measured process temperature value.
If the temperature sensor fails, the Flow output will go to Bad status.
Backup
The transmitter will use the actual measured Process Temperature value.
If the temperature sensor fails, the transmitter will use the value shown in Fixed PT .
Fixed The transmitter will always use the temperature value shown in Fixed PT .