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圧力単位換算

タイヤ、気象、血圧の測定値について、psi から bar、bar から psi、kPa、atm、hPa、mmHg、inHg に換算し、正確な換算係数の連鎖を示します。

更新日 検証済みの例：4

変換元の単位で数値を入力するか、単位付きの数値を入力します
試す
変換後の値
bar
変換後の値: 2.20632233381 bar
有効桁数：12；最も近い値へ、等距離ならゼロから遠い値へ
単位換算
32 psi ≈ 2.206322 bar
換算係数
0.0689475729317
正確さ
定義は正確、結果は循環小数

32 psiは約2.206322 barです。 1単位のポンド毎平方インチは約0.06894757 barです。

同じ量を各単位で表示

psi32 psiバール2.206322 bar
32 psiを各圧力単位で表示 行数：11
単位値定義
pascal (Pa)220,632.2基本単位
hectopascal (hPa)2,206.3221 hPa = 100 Pa、正確な値
キロパスカル (kPa)220.63221 kPa = 1,000 Pa、正確な値
megapascal (MPa)0.22063221 MPa = 1,000,000 Pa、正確な値
バール2.2063221 bar = 100,000 Pa、正確な値
standard atmosphere (atm)2.1774711 atm = 101,325 Pa、正確な値
ポンド毎平方インチ (psi)321 psi = 4.4482216152605/0.00064516 Pa、正確な値
millimetre of mercury (mmHg)1,654.8781 mmHg = 133.322387415 Pa、正確な値
torr (Torr)1,654.8781 Torr = 101,325/760 Pa、正確な値
inch of mercury (inHg)65.152651 inHg = 3,386.389 Pa、近似値（0 °C での慣用値）
kilogram-force per cm² (kgf/cm²)2.2498231 kgf/cm² = 98,066.5 Pa、正確な値
計算方法 S

  1. ポンド毎平方インチからpascalへ換算

    32 psi×4.44822161526050.00064516 Papsi=220,632.233381 Pa32\ \text{psi} \times \tfrac{4.4482216152605}{0.00064516}\ \tfrac{\text{Pa}}{\text{psi}} = 220{,}632.233381\ \text{Pa}

    1 psi = 4.4482216152605/0.00064516 Pa、正確な値

  2. pascalからバールへ換算

    220,632.233381 Pa÷100,000 Pabar=2.20632233381 bar220{,}632.233381\ \text{Pa} \div 100{,}000\ \tfrac{\text{Pa}}{\text{bar}} = 2.20632233381\ \text{bar}

    1 bar = 100,000 Pa、正確な値

  3. 統合した換算係数

    1 psi=4.44822161526050.00064516100,000 bar≈0.0689475729317 bar1\ \text{psi} = \frac{\tfrac{4.4482216152605}{0.00064516}}{100{,}000}\ \text{bar} \approx 0.0689475729317\ \text{bar}

    両方の単位の定義は正確ですが、変換後の値は循環小数です。有効数字12桁で表示します。

圧力単位換算について

Each pressure unit is a fixed number of pascals (newtons per square metre). The bar is exactly 100,000 Pa, the standard atmosphere 101,325 Pa and the torr 1/760 atm. The psi, one pound-force per square inch, is about 6,894.757 Pa, fixed exactly by the 1959 pound, standard gravity (9.80665 m/s²) and the 25.4 mm inch.

The default converts a 32 psi tyre pressure to 2.2063 bar. Weather maps use hectopascals (1 hPa = 1 mbar; standard sea-level pressure is 1,013.25 hPa), and blood pressure is recorded in millimetres of mercury.

Gauge and absolute readings convert with the same factor but are not interchangeable: a tyre gauge shows pressure above the surrounding air, so 32 psi on the gauge is about 46.7 psi absolute at sea level. The inch of mercury uses the conventional value at 0 °C and is marked approximate.

計算例

32 psi tyre pressure in bar

値
32 psi
変換元
pound per square inch (psi)
変換先
バール
変換後の値
2.2063223338 bar

照合元：1 psi = 4.4482216152605 N ÷ (0.0254 m)² (NIST SP 811 App. B); 32 psi = 8896443230521/4032250000000 bar (Python 3.8 fractions from the legal definitions)

1 atm in psi

値
1 atm
変換元
standard atmosphere (atm)
変換先
pound per square inch (psi)
変換後の値
14.6959487755 psi

照合元：101325 Pa ÷ 6894.757293168… Pa (Python 3.8 fractions from the legal definitions)

760 torr is 1 atm

値
760 Torr
変換元
torr (Torr)
変換先
standard atmosphere (atm)
変換後の値
1 atm
正確さ
正確

照合元：1 torr = 101325/760 Pa by definition (NIST SP 811 App. B)

1 inHg (conventional value)

値
1 inHg
変換元
inch of mercury (inHg)
変換先
pascal (Pa)
変換後の値
3,386.389 Pa
正確さ
近似

照合元：NIST SP 811 App. B.9: inch of mercury (0 °C) = 3.386389 E+03 Pa

よくある質問

How do I convert psi to bar?

Divide by 14.5038, or multiply by 0.0689476. A bar is 100,000 Pa and a psi 6,894.757 Pa, so 1 bar = 14.5038 psi. A 32 psi tyre is 2.2063 bar, and a 2.5 bar tyre is 36.26 psi.

Is 1 bar the same as 1 atmosphere?

No, though they are within 1.3%. The bar is exactly 100,000 Pa, while the standard atmosphere is exactly 101,325 Pa, which is 1.01325 bar, 14.696 psi or 760 mmHg. The atmosphere was set to match average sea-level air pressure, which is why weather charts centre on 1,013.25 hPa.

What is the difference between psig and psia?

psig is gauge pressure, measured relative to the surrounding air; psia is absolute pressure, measured from a vacuum. At sea level psia = psig + 14.696. Tyre and compressor gauges read psig, so a flat tyre shows 0 psig while still holding 14.7 psia of air. The converter treats both alike, so keep input and output the same kind.

Are mmHg and torr the same?

Almost. A torr is exactly 1/760 of a standard atmosphere, 133.322368 Pa, while the conventional millimetre of mercury is 133.322387415 Pa; they differ by about 0.14 parts per million. For blood pressure the difference never matters: 120/80 mmHg is 16.0/10.7 kPa either way.

How do I convert inches of mercury to hPa?

Multiply by 33.8639: 29.92 inHg is 1,013.2 hPa, the standard altimeter setting in US aviation. This converter uses the conventional inch of mercury at 0 °C, 3,386.389 Pa (NIST SP 811), and marks results that use it as approximate because mercury's density changes with temperature.

「圧力単位換算」の精度はどのくらいですか？

精度は入力値と計算方法の前提に依存します。十進演算には有効数字50桁を使いますが、推定、数値計算手法、元データの精度はそれより低い場合があります。表示の丸め処理でこれらの制約がなくなるわけではありません。 独立した出典の解答と照合した計算例：4。 例えば、「32 psi tyre pressure in bar」は1 psi = 4.4482216152605 N ÷ (0.0254 m)² (NIST SP 811 App. B); 32 psi = 8896443230521/4032250000000 bar (Python 3.8 fractions from the legal definitions)と照合しています。

この計算方法の出典は何ですか？

NIST SP 811 (2008), Guide for the Use of the SI, Appendix B — conversion factors; NIST Handbook 44, Appendix C — General tables of units of measurement.

この計算機について

xto=xfrom×ffromftof=one unit expressed in Pa\begin{gathered} x_{\text{to}} = x_{\text{from}} \times \dfrac{f_{\text{from}}}{f_{\text{to}}} \\ f = \text{one unit expressed in } \text{Pa} \end{gathered}

出典

  1. NIST SP 811 (2008), Guide for the Use of the SI, Appendix B — conversion factors
  2. NIST Handbook 44, Appendix C — General tables of units of measurement

出典と照合済み

この計算機には、独立した出典の解答を使った計算例が 4 件あります。テストに組み込まれており、ここでも実行できます。

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