Internal shunt resistor scaling
Use shunt scaling for applicable eDAQXR layers and MX modules.
Before starting the shunt scaling task, define all pertinent parameters for the bridge configuration, including the Shunt resistor and Shunt polarity.
Note that the % Dev parameter is a read only parameter that is automatically updated after the shunt scaling task is completed. The % Dev is the calculated percent deviation from the ideal shunt span based on the bridge type, bridge resistance, lead wire resistance and shunt resistance. In brief, it provides feedback to the user on the accuracy of the shunt scaling experiment.
NOTE
Shunt polarity is based on electrical units scaling (i.e., mV/V scaling). If the sensor scaling slope is negative, the shunt polarity in output units is in the opposite direction. For example, the Up Scale option would result in a negative swing in the output data.
See Shunt scaling based on a known shunt scaling
Select the channel or channels to be scaled and click Shunt Scaling.
When this task starts, the GUI displays some temporary parameter settings in the grid interface. These can be ignored as the user defined settings are restored later. The Units and Physical span values can be modified before or after the Electrical zero and Electrical span are measured.
NOTE
For the MX1615B-R module only, to optimize the scaling accuracy, the CX23-R/eDAQXR automatically uses the AC Excitation mode and the largest Excitation range available during sensor scaling. If necessary, the Excitation mode and range revert to the user-defined values after shunt scaling is completed or canceled. In this situation, the channel requires zeroing and the GUI prompts the user to do this.
Perform shunt scaling in three steps:
NOTE
It is recommended to select the Use system defined sensor scaling filters option in the System preferences to minimize the effects of noise on the accuracy of scaling measurements.