RE #26848 Add documentation for loading a calibration

docs/source/interfaces/Engineering Diffraction 2.rst

@@ -38,13 +38,18 @@ Calibration
 -----------
 
 This tab currently provides a graphical interface to create new calibrations
-and visualise them.
+and visualise them. It also allows for the loading of GSAS parameter files created
+by the calibration process to load a previously created calibration into the interface.
 
-The "Plot Output" check-box will plot vanadium curves and ceria peaks. Four plots
-will be generated (for ENGINX), one of each plot for each of the detector banks.
+When loading an existing calibration, the fields for creating a new calibration will be
+automatically filled, allowing the recreation of the workspaces and plots generated by
+creating a new calibration.
 
-Creating a new calibration file generates 3 GSAS instrument parameters files,
-one all banks and separate ones for each individual bank. All 3 files are written
+The "Plot Output" check-box will plot vanadium curves and ceria peaks for new calibrations.
+Four plots will be generated (for ENGINX), one of each plot for each of the detector banks.
+
+Creating a new calibration file generates 3 GSAS instrument parameter files,
+one covering all banks and separate ones for each individual bank. All 3 files are written
 to the same directory:
 
 `Engineering_Mantid/Calibration/`
@@ -54,8 +59,7 @@ in the base directory:
 
 `Engineering_Mantid/User/RBNumber/Calibration/`
 
-Currently, the `Engineering_Mantid` directory is created in the currently logged in
-user's home directory.
+Currently, the `Engineering_Mantid` directory is created in the current user's home directory.
 
 Parameters
 ^^^^^^^^^^
@@ -65,4 +69,7 @@ Vanadium Number
 
 Calibration Sample Number
     The run number for the calibration sample run (such as ceria) used to calibrate
-    experiment runs.
\ No newline at end of file
+    experiment runs.
+
+Path
+    The path to the GSAS parameter file to be loaded.
\ No newline at end of file