Fisher FIELDVUE DLC3010 Instruction Manual page 62

Configuration
October 2014
The calibration process flows as follows:
D Change the PV mode to Level.
D Set the Level Offset to zero.
D Set the Range Values to:
LRV = 0.0,
URV = displacer length.
D Capture Zero at the lowest process condition (that is, with the displacer completely submerged in the fluid of
the lowest density ­ NOT dry).
D Set Specific Gravity to the difference between the SGs of the two fluids (for example, if SG_upper = 0.87 and
SG_lower = 1.0, enter a specific gravity value of 0.13).
D Set up a second process condition more than 5% of span above the minimum process condition, and use the Trim
Gain procedure at that condition. The gain will now be initialized correctly. (The instrument would work fine in
this configuration for an interface application. However, if you have a density application, it won't be possible to
report the PV correctly in engineering units if the instrument calibration is concluded at this point.)
Since you now have a valid gain:
D Change the PV mode to Interface or Density,
D reconfigure the fluid SGs or range values to the actual fluid values or extremes, and
D use the Trim Zero procedure in the Partial Calibration menu to back­compute the theoretical zero­buoyancy
angle.
The last step above will align the value of the PV in engineering units to the sight glass observation.
Note
Information on simulating process conditions is available in the
Controllers and Transmitters instruction manual supplement
sales office or at www.fisher.com.
Following are some guidelines on the use of the various sensor calibration methods when the application uses an
overweight displacer:
Weight‐based: Use two accurately known weights between minimum and maximum buoyancy conditions. The full
displacer weight is invalid because it will put the unit on a stop.
Min/Max: Min now means submerged in the lightest fluid and Max means submerged in the heaviest fluid.
Two point: Use any two interface levels that actually fall on the displacer. Accuracy is better if the levels are farther
apart. The result should be close if you can move the level even 10%.
Theoretical: If the level cannot be changed at all, you can enter a theoretical value for torque tube rate manually. In
this case you would not be able to Capture Zero at the 0% interface condition.
62
Simulation of Process Conditions for Calibration of Fisher Level
(D103066X012), available from your Emerson Process Management
Instruction Manual
D102748X012