A rain gauge is a device for measuring rainfall. The inscription on the gauge stand records that King Jeongjo (r.1776-1800) hoped for rain during a severe drought in the 6th year of his reign, 1782, so he regulated the production standard of rain gauges, based on the reconstruction of the original invented under King Sejong's (r.1418-1450) rule. These gauges were installed in the Astronomical and Meteorological Observatory in every county and prefecture. During the reign of his predecessor King Yeongjo (r. 1724-1776) they had also been installed in Changdeok and Gyeonghui Palaces, two capitals (today’s Seoul and Gaeseong) and every province.

Although the first rain gauge in Korea is widely known to have been invented by Jang Yeong-sil, an article in the Annals of King Sejong clarifies that on the 29th of the 4th lunar month, 1441, King Sejong’s crown prince, later King Munjong, devised a copper vessel and came up with the idea of using a ruler to measure the rainfall in the vessel. The Annals also mention on the 18th day of the 8th lunar month, 1441, a cylindrical barrel was cast in iron in order to improve inaccuracy of measurement.

The original barrel accompanying this rain gauge stand was lost during the Korean War. The currently exhibited barrel is a replica based on Geumyeong Rain Gauge (Treasure No. 561), the only surviving rain gauge dated to the Joseon period.