Quick Start Guide

Quick Start Guide
D103214X012
DLC3010 Digital Level Controller
September 2014
28
until sufficient buoyancy has developed to allow the linkage to move. In that case, use the calibration procedure for
overweight displacers below.
After the initial calibration:
For a level application— Go to the Sensor Compensation menu and use 'Enter constant SG' to configure the instrument
for the target process fluid density.
For an interface application— Change the PV mode to Interface, verify or adjust the range values presented by the
Change PV mode procedure, and then use 'Enter constant SG' to configure the instrument for the SGs of each of the
target process fluids.
For a density application— Change the PV mode to Density, and establish the desired range values in the 'Change PV
mode' procedure.
If the target application temperature is considerably elevated or depressed from ambient, refer to the DLC3010
instruction manual (D102748X012) for information on temperature compensation.
If you are able to adjust both process fluids, the Two Point Calibration is recommended.
If you are unable to carry out Min/Max or Two Point Calibration, then establish zero buoyancy and capture zero. Next,
establish a minimum 5% span above the Lower Range Value and Trim Gain.
If you only have a single fluid for calibration, run through Instrument Setup and verify all displacer data is correct. Set
Level Offset to 0. Select Level application with direct action, and enter SG=1.0 (water) or actual SG of test fluid if
different than 1.0. Proceed with Min/Max or Two Point Calibration.
Note
Information on computing precise simulation of this effect is available in the Simulation of Process Conditions for Calibration of
Fisher Level Controllers and Transmitters instruction manual supplement (D103066X012), available from your Emerson Process
Management sales office or at www.fisher.com.
Calibration with an Overweight Displacer
When the sensor hardware is sized for greater mechanical gain (as it is in some interface or density measurement
applications), the dry displacer weight is often greater than the maximum permissible load on the torque tube. In this
situation it is impossible to 'capture' the zero buoyancy rotation of the torque tube, because the linkage is lying on a
travel stop at that condition.
The 'Capture Zero' routine in the Partial Calibration menu group will therefore not function correctly in the target PV
modes of interface or density when the displacer is overweight.
The Full Calibration routines: Min/Max, TwoPoint, and Weight, will all work correctly at the actual process conditions
when in interface or density mode, because they backcompute the theoretical zerobuoyancy angle instead of
capturing it.
If it is necessary to use the Partial Calibration methods when the displacer is overweight, the following transformation
may be used:
An interface or density application can be mathematically represented as a level application with a single fluid whose
density is equal to the difference between the actual SGs of the fluid covering the displacer at the two process
extremes.