The Torque Balance Pressure Transmitter Can Be Remotely Controlled Without An External Power Supply

The torque balance pressure transmitter is a classic and mechanical pressure measurement and remote transmission device. It uses levers, balance weights and electromagnetic feedback systems to proportionally convert the input pressure signal into a standard 4-20mA DC current signal output.

1. High reliability and environmental adaptability: The pure mechanical structure is robust, resistant to vibration, radiation, and high temperatures, and can still be applied in extreme environments such as nuclear power plants.
2. Intrinsic two-wire system: It is naturally a two-wire 4-20mA output and does not require additional power supply.
3. Wide range adjustment: By moving the range pivot (range wheel) on the lever, the range ratio can be significantly adjusted (up to 10:1 or more), providing good on-site adaptability.
4. Stable zero point: The mechanical balance system has a stable zero point with minimal long-term drift.
5. No external power supply required (for the sensor itself): The force balance principle itself does not require power, but the amplifier does. The overall system remains a two-wire power supply.

• Maintenance and replacement of old plants: In a large number of still-operating old devices.
• Special occasions: In the nuclear industry, high-radiation, and strong electromagnetic interference environments, it has unique advantages because it does not rely on semiconductor devices.
• Teaching and principle understanding: Its principle is intuitive and is an excellent teaching aid for understanding the "input-feedback-output" closed-loop concept of transmitters.

The torque balance pressure transmitter is a great milestone in the history of industrial automation. It was the first to achieve on a large scale the reliable conversion of on-site physical quantities (pressure) into standard current signals, laying the foundation for centralized control (the predecessor of DCS).