Most humidity calibrator are built using one of 2 options. Split-stream humidity control is used in a mixed-flow generator. Dry gas is split into two portions and pulled into the generator using this technique. The other component is blended in until the desired humidity output is attained after one part is partially or entirely saturated with water vapour. The wet air's humidity as well as the mixing ratio determines the humidity. The test chamber's high-volume fan provides constant humidity and temperature levels. Two chambers make up a generator with two pressures. The first one, referred to as the saturator, has air that is highly pressurized and saturated with water vapour. The second chamber, known as the test chamber, receives the air from the saturator. Lower than normal is the test chamber.