The dew point can found by finding the exact temperature at which dew forms. Water in the air becomes dew when it condenses and forms on a solid surface.
The dew point is the temperature at which water vapor put under constant barometric pressure condenses and becomes dew. It is an indication of water-to-air saturation and can never be higher than the current temperature. If the temperature of an area falls, then the dew point must fall.
By capturing air and manipulating temperatures, the dew point of a specific area can be found. When captured air is put under constant barometric pressure, the temperature of the air can then be lowered or raised to cause condensation to form. When the dew point is reached, the exact temperature can then be recorded.
High relative humidity is an indicator that the dew point is close to the temperature of the air. When it reaches 100 percent relative humidity, it means that the air is at the highest point of water saturation. At this point, the dew point is equal to the air temperature.
If there is no constant barometric pressure in the air, then the dew point is a product of absolute humidity, which is the mass of water per unit volume of air. If the pressure and temperature rise, then the dew point increase while the relative humidity decreases. If the absolute humidity falls, then the dew point returns to where it normally occurs.