You can delete measurement tools one by one and remove all measurement tools.
After deleting a measurement tool, if a delta calculation is related with the deleted tool, the delta will also be deleted.
Right-click on a measurement tool in image and select Delete Measurement.
Select a measurement tool and press the Delete key on the keyboard.
Right-click any location on the image (except locations within measurement tools) and select Remove All Measurements.
In the toolbar, click to remove all measurement tools.
The way of deleting one measurement tool also applies to deleting a delta.
Another way is that in the Measurement Value window, right-click on one delta, and select Delete.
Go to to open the Measurement Value window.