GAS DETECTION METHOD, PROGRAM, CONTROL SYSTEM, AND GAS DETECTION SYSTEM

A gas detection method includes a first process, a second process, and a third process. The first to third process include changing routes to be followed by gases into first to third routes, respectively. The first route follows a first passage, a sensor chamber, and a second passage in this order. The second route follows a sample gas supply path, which bypasses a filter unit, and the sensor chamber in this order and allows the gas to be exhausted without letting the gas pass through the filter unit while flowing from the sensor chamber. The third route follows the first passage and the sensor chamber in this order and allows the gas to be exhausted without letting the gas pass through the filter unit while flowing from the sensor chamber.