Limited space oxygen content monitoring device, monitoring method and manufacturing method

The invention provides a limited space oxygen content monitoring device, a monitoring method and a manufacturing method, and relates to the technical field of limited space operation in a transformer substation, a box body is internally provided with a measuring unit, a communication unit, an energy supply unit, an alarm unit and a processor; the measuring unit collects the oxygen concentration in the limited space and transmits the oxygen concentration to the processor; the processor compares the obtained oxygen concentration with a preset oxygen concentration threshold value, and if the oxygen concentration is lower than the threshold value, an alarm is given through the alarm unit; the processor is connected with the communication unit to transmit the oxygen concentration to the cloud server, and a user is in communication connection with the cloud server through a mobile terminal to obtain oxygen concentration data in a limited space. Under the condition that a plurality of operation sites work at the sam