Emerson fisher DLC3100 displacer level transmitter
Emerson fisher DLC3100 displacer level transmitter
Principle of Operation FISHER DLC3100 displacer level transmitter
The fisher DLC3100 digital level controller is a loop-powered instrument fisher DLC3100 that measure changes in liquid level, level of an interface between two liquids, or density of a liquid. A level, density, or interface level change in the measured fluid causes a change in the displacer buoyancy (figure 6). This change is transferred to the torque tube assembly displacer level transmitter. As the measured fluid changes, the torque tube assembly rotates. The rotary motion of the torque tube is transferred to the digital level controller lever assembly (figure 6). The rotary motion moves a magnet attached to the lever assembly, changing the magnetic field that is sensed by the Hall-effect sensor. The sensor converts the magnetic field signal to a varying electronic signal, which is processed digitally to provide linearity corrections, sensitivity adjustmentdisplacer level transmitter, and temperature compensation. The signal is interpreted as a buoyancy change by reference to the stored torque rate, coupling point, and moment arm data. The buoyancy change in turn is interpreted as a level, interface, or density change by reference to stored displacer volume, specific gravity, and displacer length data. In level or interface modes, the correction for displacer motion is then added, as well as user-supplied offset to change the PV reference from the bottom of the displacer or correct for a coupling point error. The resultant primary variable (PV) is then compared to PV alarm thresholds (if enabled) and used to set status bits and/or trigger the analog alarm current. If the alarm is not triggered, the PV is used to generate 4-20 mA analog and 0-100% range digital signals by reference to the stored upper and lower range values. The resultant analog command displacer level transmitter is limited at the saturation values to allow discrimination between saturated and alarm signals. Figure 6. Cutaway View of Fisher 249 Displacer Sensor with fisher DLC3100 FIELDVUE DLC3100 Digital Level Controller displacer level transmitter
displacer level transmitter
