4-20 mA Current Loop Output

A 4-20 mA current loop output is a standard electrical signal used by pressure transmitters to communicate measured pressure values. It involves a constant current flowing through a closed loop, with the magnitude of the current directly proportional to the measured pressure.

Specificity:

• Robustness: The current loop is inherently resistant to electrical noise, making it reliable in industrial environments.
• Standardization: The 4-20 mA range is widely adopted, ensuring compatibility between different devices.
• Efficiency: The use of a single pair of wires for both power and signal transmission simplifies installation.
• Linearity: The output current is linearly related to the measured pressure, facilitating easy data processing.

Applications:

• Industrial process control: Widely used for monitoring and controlling pressure in various industries, such as oil and gas, chemical processing, and power generation.
• Remote sensing: Suitable for transmitting pressure data over long distances due to the signal’s immunity to noise.
• Hazardous environments: Can be employed in areas with potentially explosive atmospheres due to its intrinsic safety characteristics.
• Data acquisition systems: Easily integrated with data acquisition and control systems for real-time monitoring and analysis.

Note: To measure the pressure value, the 4-20 mA current is typically converted into a voltage by passing it through a known resistance. This voltage can then be interpreted by a display or control system.

While other output types exist, the 4-20 mA current loop remains a preferred choice for many pressure measurement applications due to its combination of robustness, accuracy, and simplicity.