Input channel scaling parameters

Before running a test, many input sensors must be scaled. Define sensor scaling parameters in Input channels.

To configure a channel for sensor scaling, first set the Scaling mode in the channel editor dialog or channel grid (Closedscreenshot).

Depending on the mode selected, different scaling parameters must be specified to define the scaling.

Sensor scaling mode Scaling parameters
Defined slope intercept Slope
Intercept
Defined zero span Electrical zero
Electrical span
Physical span
Defined two point Electrical 1
Physical 1
Electrical 2
Physical 2
Experimental two point See Experimental two point scaling
Internal shunt resistor See Internal shunt resistor scaling
Defined sensitivity factor Sensitivity factor
Strain gage Strain gage factor
Bridge factor

ClosedScaling parameters

  • Scaling mode: Set the channel scaling mode.
    • Defined slope intercept: Specify the Slope and Intercept of the scaling line.
    • Defined zero span: Specify the Electrical zero of the sensor scaling line. Enter both the Electrical span and the Physical span.
    • Defined two point: Specify the Electrical 1, Physical 1, Electrical 2 and Physical 2 points to define the scaling line.
    • Experimental two point: Use the Experimental two point scaling option to define the two point parameters based on experimental measurements.
    • Internal shunt resistor: Use internal shunt resistor scaling for applicable modules with a shunt resistor. Specify the Shunt resistor and Shunt polarity parameters before starting experimental scaling. (Note that % Dev is the percent deviation from the ideal shunt voltage swing for Internal shunt resistor scaling mode. This is set by the system and is read only.) See the topics Define known shunt and Equivalent strain calculator for more information about these shunt scaling tools for calculating Physical span.
    • Defined sensitivity factor: Specify the Sensitivity which is typically defined in the data sheet for bridge sensors (e.g., PSI per mV/V, Newton per mV/V, etc.). The Defined sensitivity factor is available for all channels that support Defined slope intercept scaling mode. Note that this scaling mode is equivalent to the Defined slope intercept mode, where the Slope is equal to the Sensitivity and the Intercept is equal to 0.
    • Strain gage: Specify the Strain gage factor and Bridge factor.
  • Sensitivity factor: Specify the Sensitivity which is typically defined in the data sheet for bridge sensors (e.g., PSI per mV/V, Newton per mV/V, etc.). The sensitivity factor is available for all channels that support Defined slope intercept scaling mode.
  • Electrical units: Electrical units of channel input. The defined sensor scaling is used to convert data from Electrical units to Physical units.
  • Calibration date: When using the channel calibration dates and locks option, the UTC calibration date (yyyy-mm-ddThh:mm:ss) is shown when the channel is calibrated. See Calibration options for more information.
  • Units: Physical units of measurement for the channel.
  • Electrical 1: Specify for Defined two point scaling mode. Automatically set after Experimental two point scaling.
  • Physical 1: Specify for Defined two point scaling mode. Automatically set after Experimental two point scaling.
  • Electrical 2: Specify for Defined two point scaling mode. Automatically set after Experimental two point scaling.
  • Physical 2: Specify for Defined two point scaling mode. Automatically set after Experimental two point scaling.
  • Electrical zero: Specify for Defined zero span scaling mode.
  • Electrical span: Specify for Defined zero span scaling mode.
  • Physical span: Specify for Defined zero span scaling mode.
  • Slope: Specify for Defined slope intercept scaling mode.
  • Intercept: Specify for Defined slope intercept scaling mode.
  • Strain gage factor: Specify for Strain gage scaling mode.
  • Bridge factor: Specify for Strain gage scaling mode.
  • Shunt resistor: Specify for Internal shunt resistor scaling mode.
  • Shunt polarity: Specify for Internal shunt resistor scaling mode.
  • % Dev: Percent deviation from the ideal shunt voltage swing for Internal shunt resistor scaling mode. This is set by the system and is read only.
  • Range min and max: Specify the expected extreme values of the channel.
  • Warning and Alarm min and max: Specify the desired values for warning and alarm thresholds.
    • Enter a real number that defines the level in physical units, or a real number followed by the ‘%’ character that defines the level as a percent of Range max or min, or leave the cell blank to inhibit the warning or alarm.
    • The percent value must be in the range of 0% to 120%.
    • The % of Range max is independent of Range min and vice-versa. For example, if Range max is set to 1000 and Range min is set to -500 and 90% is used for both alarm levels, the alarms trip when the data value becomes > 900 or <-450. If the user changes the Range min to -600, the Min alarm threshold changes to -540. However, the Max alarm threshold does not change (i.e., it is still 900).
    • The values of the warnings and alarms, in terms of real numbers, must satisfy the following condition for all defined parameters:
      Min alarm threshold < Min warning threshold < Max warning threshold < Max alarm threshold.
    • A min or max warning will show a yellow background for the numbers.
    • A min or max alarm will show a red background for the numbers.
  • Max electrical: This field is applicable to MXB modules only. It is used to set the signal conditioner gain and resultant measurement range.

See Input channel zero parameters for more information.