Editing Spirit level (section)

==Sensitivity==
Sensitivity is an important specification for a spirit level, as the device's accuracy depends on its sensitivity. The sensitivity of a level is given as the change of angle or gradient required to move the bubble by unit distance. If the bubble housing has graduated divisions, then the sensitivity is the angle or gradient change that moves the bubble by one of these divisions. {{cvt|2|mm|in|3}} is the usual spacing for graduations; on a surveyor's level, the bubble will move {{convert|2|mm|abbr=on}} when the vial is tilted about 0.005 degree. For a precision machinist level with {{convert|2|mm|abbr=on}} divisions, when the vial is tilted one division, the level will change {{cvt|0.04|mm|in}} one meter from the pivot point, referred to by machinists as 5 tenths per foot. This terminology is unique to machinists and indicates a length of 5 tenths ''of'' 1 thousandth of an inch.<ref>{{cite web | url=https://www.machinistguides.com/how-to-read-machine-shop-numbers-values/ | title=Beginner's Guide to Reading Machine Shop Numbers & Values | date=24 November 2021 }}</ref><ref>{{cite web | url=https://www.thediyenthusiast.com/tape-measures-and-levels/the-best-spirit-level/ | title=Sensitivity & Accuracy of Spirit Level Vials | date=13 December 2022 }}</ref>