Summary:

Absolute humidity: The pressure of the water vapor in the air or the mass of the water vapor in the air per unit volume is called the absolute humidity of the air. The unit of absolute humidity is expressed in terms of the height of the millimeter mercury column. The degree of dryness and humidity of air is related to the amount of water vapor in the air per unit volume. At a certain temperature, the greater the water vapor density in a certain volume of air, the greater the pressure, the smaller the density and the lower the air pressure. Therefore, the pressure of water vapor in the air is usually used to express the humidity.

Relative Humidity: The percentage of the actual water vapor density in the air and the saturated water vapor density at the same temperature is called the relative humidity of the air. It can also be interpreted as the absolute humidity of the air at a certain temperature, the percentage of the saturated vapor pressure at the same temperature, called the relative humidity of the air at that time. In fact, many humidity-related phenomena are not directly related to absolute humidity, but directly related to the degree of water vapor saturation. Therefore, a new concept that can express the degree of saturation of water vapor in the air is proposed. . It is also a way of expressing air humidity. Since the density of steam is proportional to the vapor pressure at the same temperature, the relative humidity is usually the actual water vapor pressure and the percentage of saturated water vapor pressure at the same temperature.

Dew point: Dew point is one of the expression methods of air humidity. It is the abbreviation of “dew point temperature”, which refers to the temperature of condensation condensation of saturated water vapor in the air. At 100% relative temperature, the dry bulb temperature, wet bulb temperature and saturation temperature at this time. And the dew point temperature is the same temperature value, and the ambient temperature is the dew point temperature. The lower the dew point temperature is than the temperature of the surrounding environment, the less the possibility of condensation, which means that the drier air is, the dew point is not affected by temperature, but it is affected by pressure. In fact, the dew point is an indicator of micro water content, but it is expressed in terms of temperature units. That is to say, the micro water content we refer to in many cases actually refers to the dew point temperature! It is common to use dew point in the case of low relative humidity, or directly in aqueous PPM, because you can't use a few zeros after the decimal point to make it meaningless. At high temperatures, there is generally no concept of relative humidity because the water has been completely vaporized and there is no concept of water content (except under high pressure).

Moisture content: Moisture content is the percentage of water and plastic in the plastic. The degree of drying of the plastic is based on the moisture content, and the lower the moisture content, the better the dehumidification effect.