Assertion: mercury's use | /r/Desires | correction
Facets:
value: for the density of mercury
type: PURPOSE
value: at the actual temperature
type: OTHER
value: normally
type: DEGREE
Source sentences:
text: The use of an actual column of mercury to measure pressure normally requires correction for the density of mercury at the actual temperature and the sometimes marked variation of gravity with location, and may be further corrected to take account of the density of the measured air, water or other fluid.