Transformation method for gas density relay, and gas density relay having online self-check function and check method thereof

A gas density relay with online self-check function, characterized in that it comprises a gas density relay body, a gas density sensor, a pressure regulating mechanism, a valve, an online check contact signal sampling unit and an intelligent control unit;

• the gas path of the pressure regulating mechanism is connected with the gas density relay body;
• the pressure regulating mechanism is configured for pressure rise and fall of the gas density relay body, to enable the contact signal action of the gas density relay body;
• the gas density detection sensor is communicated with the gas density relay body;
• the online check contact signal sampling unit is connected with the gas density relay body and configured to sample the contact signal of the gas density relay body under the ambient temperature;
• one end of the valve is provided with an interface connected with the electrical equipment, the other end of the valve is connected with the gas density relay body, or with the gas path of the pressure regulating mechanism to connect the valve with the gas density relay body;
• the intelligent control unit is connected with the gas density sensor, the pressure regulating mechanism, the valve and the online check contact signal sampling unit, respectively;
• the unit is configured to manage the closing or opening of the valve, control the pressure regulating mechanism, collect pressure values and temperature values and/or gas density values, as well as detect the contact signal operating value and/or contact signal return value of the gas density relay body;
• the contact signals include alarm signals and/or blocking signals.