Barometric altimeter

Japanese: 気圧高度計 - きあつこうどけい

…The aneroid barometer is easier to use than the mercury barometer and is used for automatic recording of atmospheric pressure and for portable use. Because air pressure decreases with height, it is also used as a barometric altimeter, with the air pressure scale of the aneroid barometer being the altitude scale.
[Atmospheric pressure units]
Since atmospheric pressure is a pressure, the units used are those of pressure.

From [Aviation Instruments]

… An airspeed indicator uses a pitot tube to display the speed of an aircraft relative to the air (airspeed). There are indicated airspeed indicators that display the measured speed as is, and true airspeed indicators that display the speed after correcting for errors due to the compressibility and density of the atmosphere. Airspeed indicators also usually incorporate a Mach meter that displays the Mach number. There are radio altimeters that measure the time it takes for a radio wave emitted from the aircraft to return to the ground and convert this into altitude to display, and barometric altimeters that measure air pressure and convert it into altitude according to a standard atmosphere. The latter has a function to correct errors based on information about the air pressure at that time from the ground, since errors occur when the ground is not at standard atmospheric pressure or when the actual atmosphere does not change with altitude as in the standard atmosphere. …

From [Altimeter]

…An instrument that measures altitude above the Earth's surface or sea level, and is used mainly in aircraft. It is broadly divided into barometric altimeters and radio altimeters. Barometric altimeters use the relationship that the air pressure decreases as the altitude increases to display the altitude (barometric altitude) calculated from the detected air pressure. …

*Some of the terminology that refers to "barometric altimeter" is listed below.

Source | Heibonsha World Encyclopedia 2nd Edition | Information

Japanese:

…水銀気圧計よりも取扱いの簡単なアネロイド気圧計は気圧の自動記録や携帯用に利用される。気圧が高さと共に減少することから，アネロイド気圧計の気圧目盛を高度目盛にした気圧高度計としても利用される。
［気圧の単位］
　気圧は圧力であるから，単位としては圧力の単位が使用される。…

【航空計器】より

…　対気速度計はピトー管を利用して航空機の空気に対する速度(対気速度)を表示するもので，測定された速度をそのまま表示する指示対気速度計と，大気の圧縮性や密度による誤差を補正して表示する真対気速度計があり，またマッハ数を表示するマッハ計を組み込んでいるものがふつうである。高度計には機上から地表に向けて発射した電波が戻ってくるまでの時間を測定して，これを高度に換算して表示する電波高度計，気圧を測定してこれを標準大気に従って高度に換算して表示する気圧高度計がある。後者は地上が標準大気圧でない場合や，実際の大気が標準大気のとおり高度とともに変化しないときには表示に誤差が生ずるので，地上からのそのときの気圧の情報に基づいて誤差を補正する機能を備えている。…