Capillarity correction

From Glossary of Meteorology

capillarity correction

As applied to a mercury barometer, that part of the instrument correction that is required by the shape of the meniscus of the mercury.

Mercury does not wet glass and consequently the shape of the meniscus is normally convex upward, resulting in a positive correction. For a given barometer, this correction will vary slightly with the height of the meniscus. The capillarity correction can be minimized by using a tube of large bore.
See barometric corrections, capillary depression, capillary action.

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