Gas concentration controller system

A gas concentration controller program used for a gas concentration controller system configured to mix a first gas and a second gas at a predetermined ratio to produce mixed gas having a predetermined concentration and is provided with:

• a first gas line that is provided with a first gas flow rate controlling mechanism for controlling a flow rate of the first gas;
• a second gas line that is provided with a second gas flow rate controlling mechanism for controlling a flow rate of the second gas;
• an output gas line that is joined by the first gas line and the second gas line and configured to output the mixed gas having the predetermined concentration;
• and
• an exhaust gas line that is connected to an upstream side of the second gas flow rate controlling mechanism in the second gas line and provided with an on/off valve and a flow rate control part configured to flow the second gas having a constant flow rate,
• the program is configured to instruct a computer to fulfill a function as a control part configured to, depending on the flow rate of the second gas flowing through the second gas line or a type of the second gas, switch on/off the on/off valve provided in the exhaust gas line.

A gas concentration controller method using a gas concentration controller system configured to mix a first gas and a second gas at a predetermined ratio to produce mixed gas having a predetermined concentration and is provided with:

• a first gas line that is provided with a first gas flow rate controlling mechanism for controlling a flow rate of the first gas;
• a second gas line that is provided with a second gas flow rate controlling mechanism for controlling a flow rate of the second gas;
• an output gas line that is joined by the first gas line and the second gas line and configured to output the mixed gas having the predetermined concentration;
• and
• an exhaust gas line that is connected to an upstream side of the second gas flow rate controlling mechanism in the second gas line and provided with an on/off valve and a flow rate control part configured to flow the second gas having a constant flow rate, the gas concentration controller method, depending on the flow rate of the second gas flowing through the second gas line or a type of the second gas, configured to switch on/off the on/off valve provided in the exhaust gas line.