Material gas concentration control system

A material gas concentration control system that is used for a material evaporation system comprising a tank to accommodate a material, an inlet line to input a carrier gas for evaporating the accommodated material into the tank and an outlet line to output a mixed gas consisting of a material gas formed of the evaporated material and the carrier gas from the tank, the material gas concentration control system comprising:

• a body that is connected to the outlet line and that has an internal flow channel for flowing the mixed gas;
• a concentration measuring sensor that measures the concentration of the material gas in the mixed gas flowing in the internal flow channel;
• and
• a first valve that is arranged downstream of the concentration measuring sensor and that adjusts the measured concentration measured by the concentration measuring sensor at a previously determined set concentration, wherein
• the concentration measuring sensor and the first valve are mounted on the body;
• the concentration measuring sensor and the first valve are arranged from the concentration measuring sensor to the first valve along the flow of the mixed gas flowing in the internal flow channel;
• the body has a connecting port that is configured to connect the outlet line and the internal flow channel;
• the concentration measuring sensor is arranged between the connecting port and the first valve.