Cloud cover meter (English spelling) nephometer

Japanese: 雲量計 - うんりょうけい（英語表記）nephometer

Cloud cover is the percentage of the entire sky that is covered by clouds, and is expressed as a number between 0 and 10. Cloud cover is generally observed by human eyes, and an instrument that aids in visual observation is called a nephelometer. It is a hemispherical birdcage-shaped wire structure that is designed so that the horizontal and vertical areas enclosed by the wire, which correspond to latitude and longitude, are equal. The eye is placed in the center of the hemisphere, and the entire sky is observed through this device. Sometimes an all-sky camera with a fisheye lens is used to take pictures and determine the area occupied by clouds. [Takeuchi Kiyohide]

Source: Heibonsha World Encyclopedia, 2nd Edition Information

Japanese:

雲量とは，雲の覆う部分の全天空に対する割合のことで，0～10の数字で表す。雲量は一般に人間の目視によって観測されており，目視観測を助ける器械を雲量計という。それは半球の鳥籠状の針金製のもので，緯度･経度に相当する横と縦の針金で囲まれた面積が等しいように作られている。，眼を半球の中心に置き，この装置を通して全天空を観測する。魚眼レンズの全天カメラで撮影し，雲の占める面積を求めることもある。【竹内清秀】

出典　株式会社平凡社世界大百科事典第２版について　情報

<<: Fritz von Unruh

>>: Linaria japonica Miq.