2Sensor Temperature Unit; 3Scaled Variable Configuration - Emerson Rosemount 3051SAL Reference Manual

Section 2: Configuration
May 2013
2.10.2 Sensor temperature unit
Fast Keys
The Sensor Temperature Unit command selects between Celsius and Fahrenheit units for the
sensor temperature. The sensor temperature output is accessible via HART only.
To select the sensor temperature unit:
1.
2.
3.
4.
2.10.3 Scaled Variable Configuration
Fast Keys
The scaled variable configuration allows the user to create a relationship/conversion between
the pressure units and user-defined/custom units. There are two use cases for scaled variable.
The first use case is to allow custom units to be displayed on the transmitter's LCD display. The
second use case is to allow custom units to drive the transmitter's 4-20 mA output.
If the user desires custom units to drive the 4-20 mA output, scaled variable must be re-mapped
as the primary variable. Refer to
The scaled variable configuration defines the following items:
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18
2, 2, 8, 3
From the Home screen, choose 2: Configure.
Choose 2: Manual Setup.
Choose 8: Device Temperatures.
Choose 3: Sensor Temperature.
2, 2, 3
"Re-Mapping device variables" on page
Scaled variable units - Custom units to be displayed.
Scaled data options - Defines the transfer function for the application
a. Linear
b. Square root
Pressure value position 1 - Lower known value point (possible 4 mA point) with
consideration of linear offset.
Scaled variable value position 1 - Custom unit equivalent to the lower known value
point (The lower known value point may or may not be the 4 mA point.)
Pressure value position 2 - Upper known value point
(possible 20 mA point)
Scaled variable value position 2 - Custom unit equivalent to the upper known value
point (possible 20 mA point)
Linear offset - The value required to zero out pressures effecting the desired pressure
reading.
Low flow cutoff - Point at which output is driven to zero to prevent problems caused by
process noise. It is highly recommended to use the low flow cutoff function in order to
have a stable output and avoid problems due to process noise at a low flow or no flow
condition. A low flow cutoff value that is practical for the flow element in the
application should be entered.
Reference Manual
00809-0200-4802, Rev BA
22.
Configuration