Which preposition to use with hygrometers

from Occurrences 1%

The barometer would be an absolutely reliable guide for the hunting man were it not for the complications already named above, complications which prevent either barometer or hygrometer from offering infallible indications of good or bad scenting days.

in Occurrences 1%

He came to England, was appointed reader to Queen Charlotte, and lived in the enjoyment of that office, and in the gratifying knowledge that Her Majesty kept his presentation hygrometer in her private apartments, to the venerable age of ninety.

to Occurrences 1%

Might not this machine be applied as an Hygrometer to some meteorological purpose?]

Which preposition to use with  hygrometers