🌬️ 空气密度计算器（含湿度）Air Density Calculator (with Humidity)

使用说明与常见问题How-to & FAQ

「空气密度计算器（含湿度）」是什么？What is the Air Density Calculator (with Humidity) tool?

由气温、气压和相对湿度计算湿空气密度：把气压分成干空气分压和水汽分压分别用理想气体定律计算后相加，饱和水汽压用 Tetens 公式。可用 °C/°F 和 hPa、kPa、inHg、mmHg，结果给出 kg/m³ 和 lb/ft³。本地处理。Work out the density of humid air from temperature, pressure and relative humidity: the pressure is split into dry-air and water-vapour parts, each goes through the ideal gas law, and the two are added, with saturation vapour pressure from the Tetens formula. Use °C or °F and hPa, kPa, inHg or mmHg; results are in kg/m³ and lb/ft³. Processed locally.

如何使用「空气密度计算器（含湿度）」？How do I use the Air Density Calculator (with Humidity) tool?

在「空气密度计算器（含湿度）」中，填写「气温」、「温度单位」、「气压（站点实际气压）」、「气压单位」、「相对湿度 %」等参数，结果会随输入实时计算并显示在下方。In the Air Density Calculator (with Humidity): Fill in "Temperature", "Temperature unit", "Pressure (actual station pressure)", "Pressure unit", "Relative humidity %"; results are recalculated instantly as you type.

为什么湿度会让空气变轻？Why does humidity make air lighter?

水蒸气的摩尔质量约 18 g/mol，比干空气约 29 g/mol 小。在同样的温度和气压下，水汽取代了部分氮气和氧气，所以湿空气密度更低。Water vapour has a molar mass of about 18 g/mol versus about 29 g/mol for dry air. At the same temperature and pressure, vapour displaces some nitrogen and oxygen, so humid air is less dense.

气压该填哪个值？Which pressure should I enter?

填所在地的实际（站点）气压。天气预报里的气压通常已换算到海平面，在高海拔地点直接使用会高估密度。Use the actual (station) pressure where you are. Forecast pressures are usually corrected to sea level, and using them at altitude overstates the density.

用了哪些常数？Which constants are used?

干空气气体常数 287.058 J/(kg·K)，水蒸气 461.495 J/(kg·K)，饱和水汽压 es = 6.1078 × 10^(7.5T/(T+237.3)) hPa（T 为 °C）。Dry-air gas constant 287.058 J/(kg·K), water vapour 461.495 J/(kg·K), and saturation vapour pressure es = 6.1078 × 10^(7.5T/(T+237.3)) hPa with T in °C.

能举个计算实例吗？Can you show a worked example?

例如在「空气密度计算器（含湿度）」中填 气温 = 15，温度单位 = °C，气压（站点实际气压） = 1013.25，气压单位 = hPa (mbar)，相对湿度 % = 0，结果区显示：空气密度：1.225 kg/m³；0.07647 lb/ft³；同条件干空气：1.225 kg/m³；水汽分压：0 hPa；饱和水汽压：17.05 hPa；与标准海平面 1.225 kg/m³ 相比：100 %；ℹ 潮湿空气比干空气轻，因为水分子比氮气和氧气轻。For example, entering Temperature = 15, Temperature unit = °C, Pressure (actual station pressure) = 1013.25, Pressure unit = hPa (mbar), Relative humidity % = 0 in the Air Density Calculator (with Humidity) gives: Air density: 1.225 kg/m³; 0.07647 lb/ft³; Dry air at same T and p: 1.225 kg/m³; Vapour pressure: 0 hPa; Saturation vapour pressure: 17.05 hPa; Versus standard sea level 1.225 kg/m³: 100 %; ℹ Humid air is lighter than dry air because water molecules are…

哪些输入会被检查？Which inputs are validated?

「空气密度计算器（含湿度）」会检查这些输入——「气温」：所选方式用到时必须填写；「气压（站点实际气压）」：必须填写，须大于 0；「相对湿度 %」：可留空；绝对值超过 10¹⁵ 的数也会被拒绝。不符合时结果区显示具体提示，不会给出数字。The Air Density Calculator (with Humidity) checks its inputs — "Temperature": required when the chosen option uses it; "Pressure (actual station pressure)": required, must be greater than 0; "Relative humidity %": optional; numbers above 10¹⁵ in absolute value are rejected too. When a value fails, the result area names the problem instead of showing a number.

有哪些选项可以调整？What options can I adjust?

「空气密度计算器（含湿度）」的设置：「气温」默认 15；「温度单位」可选 °C、°F、K（默认 °C）；「气压（站点实际气压）」默认 1013.25；「气压单位」可选 hPa (mbar)、kPa、inHg、mmHg、Pa（默认 hPa (mbar)）；「相对湿度 %」默认 0。每次生成结果都按当前设置处理。Settings in the Air Density Calculator (with Humidity) — "Temperature" default 15; "Temperature unit": °C, °F, K (default °C); "Pressure (actual station pressure)" default 1013.25; "Pressure unit": hPa (mbar), kPa, inHg, mmHg, Pa (default hPa (mbar)); "Relative humidity %" default 0. The result always uses the current settings.

计算结果可以用于作业或工程吗？Can I use the results for homework or engineering?

「空气密度计算器（含湿度）」使用教科书标准公式（公式写在说明和常见问题中），适合学习和估算核对；涉及安全的工程设计请以规范和实测为准。The Air Density Calculator (with Humidity) uses standard textbook formulas (given in the description and FAQ), which is good for learning and checking estimates; for safety-critical engineering follow codes and measured values.

「空气密度计算器（含湿度）」免费吗？需要注册吗？Is the Air Density Calculator (with Humidity) free? Do I need an account?

「空气密度计算器（含湿度）」完全免费，无需注册或安装，打开网页即可使用，手机和电脑都能用；输入的内容只在你的浏览器本地处理。The Air Density Calculator (with Humidity) is completely free with no sign-up or install and works on phones and desktops; what you enter is processed only in your browser.