noun
column of mercury; mercury column
Refers to the column of mercury in a barometer or thermometer. Common in technical and weather-related contexts.
気圧が下がると、水銀柱が下がる。
When atmospheric pressure drops, the mercury column falls.
この温度計の水銀柱は壊れている。
The mercury column in this thermometer is broken.
気圧計 is a barometer, the instrument that often contains a 水銀柱.
Compound of 水銀 (mercury) and 柱 (pillar, column). The term is straightforward and describes the physical column of mercury used in scientific instruments.