Emerson Micro Motion 2700 Configuration And Use Manual page 100

Integrate the meter with the control system
Ensure that the measurement unit for the configured process variable has been set as
desired.
Procedure
Set LRV and URV as desired.
• LRVis the value of mA Output Process Variable represented by an output of 4 mA. The
default value for LRV depends on the setting of mA Output Process Variable. Enter LRV
in the measurement units that are configured for mA Output Process Variable.
• URV is the value of mA Output Process Variable represented by an output of 20 mA.
The default value for URV depends on the setting of mA Output Process Variable. Enter
URV in the measurement units that are configured for mA Output Process Variable.
Tip
For best performance:
• Set LRV ≥ LSL (lower sensor limit).
• Set URV ≤ USL (upper sensor limit).
• Set these values so that the difference between URV and LRV is ≥ Min Span (minimum span).
Defining URV and LRV within the recommended values for Min Span, LSL, and USL ensures that the
resolution of the mA Output signal is within the range of the bit precision of the D/A converter.
The mA Output uses a range of 4–20 mA to represent mA Output Process Variable.
Between LRV and URV, the mA Output is linear with the process variable. If the process
variable drops below LRV or rises above URV, the transmitter posts an output saturation
alert.
Default values for Lower Range Value (LRV) and Upper Range
Value (URV)
Each option for mA Output Process Variable has its own LRV and URV. If you change the
configuration of mA Output Process Variable, the corresponding LRV and URV are loaded
and used.
Table 6-6:
Process variable
All mass flow variables
All liquid volume flow variables
All density variables
All temperature variables
Drive gain
Gas standard volume flow
External temperature
External pressure
92
Default values for Lower Range Value (LRV) and Upper Range Value (URV)
LRV
–200.000 g/sec
–0.200 l/sec
0.000 g/cm
–240.000 °C
0.00%
–423.78 SCFM
–240.000 °C
0.000 bar
Micro Motion Model 2700 Transmitters with Intrinsically Safe Outputs
URV
200.000 g/sec
0.200 l/sec
3
10.000 g/cm
450.000 °C
100.00%
423.78 SCFM
450.000 °C
100.000 bar
3