noun
hypsometer; altimeter
A scientific instrument for measuring height or altitude, typically used in surveying, meteorology, or forestry.
測高器を使って山の高さを測る。
Measure the height of the mountain using a hypsometer.
Compound of 測 (measure), 高 (height), and 器 (instrument). The reading そっこう is the on'yomi of 測高, with き as the on'yomi of 器.