Maintenance-free gas density relay and cross-checking method therefor

A gas density relay, comprising:

• a gas density relay body, first gas density detection sensors and a controller, wherein
• the first gas density detection sensors are in communication with the gas density relay body on gas paths and are used for acquiring pressure values and temperature values, and/or gas density values;
• the controller is connected to the gas density relay body and/or the first gas density detection sensors, and receives and/or computes data monitored by the gas density relay body and the first gas density detection sensors;
• the controller compares and checks whether a first pressure value and a second pressure value are the same;
• and/or the controller compares and checks whether a first temperature value and a second temperature value are a same gas temperature;
• or the controller compares and checks whether a first density value and a second density value are the same;
• and when the first pressure value and the second pressure value are the same, and/or when the first temperature value and the second temperature value are the same, and/or when the first density value and the second density value are the same, the controller acquires a current working state of a monitoring part of the gas density relay;
• or,
• the controller transmits received data to a backend server, and the backend server compares and checks the first pressure value and the second pressure value acquired at a same gas pressure;
• and/or the backend server compares and checks the first temperature value and the second temperature value acquired at a same gas temperature;
• or the backend server compares and checks the first density value and the second density value acquired at a same gas density to acquire the current working state of the monitoring part of the gas density relay,
• one or both of the first pressure value and the second pressure value being from the first gas density detection sensors or the gas density relay body, one or both of the first temperature value and the second temperature value being from the first gas density detection sensors or the gas density relay body, and one or both of the first density value and the second density value being from the first gas density detection sensors or the gas density relay body.