Merge pull request #1451 from discip/CJC_follow-up_II

cleared up some wording along with some typo fixes

Documentation/Settings.md

@@ -130,7 +130,13 @@ Flash temperature reading at idle if tip is hot
 Note:
 If the difference between the target temperature and the measured temperature is less than 5°C, **calibration is NOT required at all**.
 
-This is used to calibrate the offset between ADC and Op-amp of the tip at next boot (Idealy it has to be done at boot, before internal components get warm.). But this setting is ***not permanent!*** It resetes after the calibration is completed (At next boot the checkbox will be unchecked!). If you need to repeat the calibration however, you have to set the checkbox *again*, unplug your device and let it cool down to room/ambient temperature & power it up, idealy while it sits on the desk.
+This is used to calibrate the offset between ADC and Op-amp of the tip **at next boot** (Ideally it has to be done at boot, before internal components get warm.). If the checkbox is set, the calibration will only be performed at the next boot. After a successful calibration the checkbox will be unchecked again! If you need to repeat the calibration however, you have to set the checkbox *again*, unplug your device and let it cool down to room/ambient temperature & power it up, ideally while it sits on the desk.
+
+Also, the calibration will only take place if both of the following conditions are met:
+- The tip must be installed.
+- The temperature difference between tip and handle must be less than 10°C. (~ ambient / room temperature)
+
+Otherwise, the calibration will be performed the next time the device is started and both conditions are met, unless the corresponding checkbox is unchecked.
 
 Hence, never repeat the calibration in quick succession!