• SIGNA MR355 / SIGNA MR360
  • Service Manual
  • 5856356-3EN Revision 5.0
  • Basic Service Documentation. Copyright General Electric Company.
  • Object ID: 00000018WIA30A27640GYZ
  • Topic ID: id_2014492 Version: 4.0
  • Date: Feb 21, 2021 9:06:13 PM

Grafidy - Examine fit

Allows examination of field error data curves to monitor progress and debug issues.

About this task

It is useful to occasionally examine the field error data curves to monitor progress and debug any issues. To view a plotted scan, select a populated cell and click Show. The measured data is plotted in red. The best-fit curve is plotted in black. For long mode data, by default the vertical axis is set to ±0.2% and the horizontal axis is displayed from 0–2 seconds. For very long mode data, by default the vertical axis is set to ±0.2% and the horizontal axis is displayed from 1-150 seconds. For short mode data, the vertical axis is displayed from –20% to 120% by default for linear on-axis data. The vertical axis for short B0 data defaults to ±0.2%. Both short mode data types default to a –1500us to 500us horizontal axis display.

Functions have been provided to allow manipulation of the plot axes.

Procedure

  1. Auto Scale - Select the [Auto Scale] radio button to toggle the state of the function. When the function is OFF, the default vertical axis limits are used. When ON, the vertical axis limits are set to the maximum and minimum values of the plotted curve.
  2. Full Plot - Select the [Full Plot] radio button to toggle the state of the function. When the function is OFF, the data collected is displayed in the plot along with the best-fit curve. When ON, the compensation exponential functions used to collect the data are added to both the collected data curve as well as the best-fit curve. Note that if there was no compensation applied for the selected component when the data was collected, selecting the [Full Plot] function does not change the appearance of the displayed curve.
  3. Default time (pull down) - Several functions are provided in the [Default Time] pull down menu to control the horizontal (time) axis. Select [Default Time] to reset the horizontal axis to the default values. Select [Full Time] to display the entire data curve collected. For example, if long data was collected out to 4s (longer than the 2s displayed by default), the [Full Time] option displays the entire curve. Select [Zoom Start] to display 0-100ms of the data curve for long mode data. If another type of data besides long is being displayed when the [Zoom Start] option is selected, the plot is not changed.
  4. [End (ms)] pull down - The [End (ms)] pull down list, and the text box next to it, let you define the minimum and maximum axis display limits for both the vertical and horizontal axes. Select the desired entry from the list and enter the value in the text box to update the display. The image below shows an example of the appearance of a data curve before and after setting the end time of the horizontal axis to 100ms.
    Figure 1. Examining fit
  5. Smooth or Unsmooth - These options are available when you right-click on the plot and control whether the data is shown after or before a multi-point sliding averaging window has been applied to the data. The default mode is to display the smoothed data. All pass/fail checks are performed on the smoothed data. Display the unsmooth data to see an indication of how the smoothing operation affected the data being used by the tool.
    Figure 2. Setting auto scale mode