Method and apparatus for measurement of dewpoint of gases

An apparatus for using a cooling gas to measure dewpoint in different gases, comprising

• a core pipe, through which the cooling gas can be routed to a measurement area, the core pipe having a closed end and an open end,
• a first side pipe, the first side pipe being connected to the core pipe adjacent the closed end for routing the cooling gas to the core pipe,
• a second side pipe, the second side pipe communicating with the open end of the core pipe for routing the gas to be measured to the measurement area,
• a light emitting source, with which the measurement area can be illuminated,
• a photodetector, with which the light penetrating through the measurement area can be detected, and
• a temperature sensor, with which the temperature of the measurement area can be detected, in order to determine the dewpoint temperature of the gas to be measured when a mist is obtained in said measurement area,
• a heater/cooler element, with which the cooling gas can be brought to a proper temperature below the dewpoint of the gas to be measured, and
• wherein the measurement area is situated adjacent the open end of the core pipe, where the second side pipe is also routed in order to mix the gas to measured with the cooling gas.