What is Humidity?
Humidity is the quantity used to express the amount of water vapor contained in air (gas), and indicates the degree of water vapor content in moist air.
Relative and absolute humidity, dew point temperature
Relative humidity
"Relative humidity" is a commonly used expression, and when people simply say "humidity," they often mean relative humidity, which is the amount of water vapor in the air expressed as a percentage, as in weather forecasts.
unit is expressed in %rh.
Absolute humidity
"Absolute humidity" represents the mass (g) of water vapor contained in unit volume (1m³) of gas.
Absolute humidity corresponds to the density of water vapor. When the temperature and pressure change, the gas volume changes, so the "absolute humidity" changes even if the amount of water vapor remains the same.
unit is g/m³.
Dew point temperature
It is expressed as the temperature at which water vapor pressure in the air is equal to the saturated water vapor pressure.
This is the temperature at which water vapor begins to turn into liquid when the temperature of a gas containing water vapor is lowered.
unit is °C.
Types of Hygrometers
There are various ways to measure humidity.
Each type has its own features such as accuracy and simplicity.
For more information, refer Types of Hygrometers.
Types and product examples based on type and shape
| Insertion Type |
Separate type |
Wall Mounting Type |
Handy type |
Ventilated type |
|
|
|
|
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HN-CP□
Temperature: 0 to 80°C
Humidity: 0 to 100%rh (no dew condensation) |
HN-CJ
Temperature: -40 to 180°C
Humidity: 0 to 100%rh (no dew condensation) |
HN-EK□
Temperature: -10 to 55°C
Humidity: 0 to 100%rh (no dew condensation) |
HN-EH□
Temperature: -20 to 70°C
Humidity: 0 to 100%rh (no dew condensation) |
MH6 (Japan Only)
Temperature: 0 to 60°C
Humidity: 0 to 100%rh (no dew condensation) |
