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0-20mA Output Pressure Transmitters

0-20mA output pressure transmitters, ideal for installations requiring a separated positive voltage supply from current loop signals for full voltage utilisation.

Pressure transmitters offering a 0-20mA current output via a 3-wire or 4-wire configuration provide a distinct solution for applications where the instrument’s power supply is intentionally separated from the signal loop. This design allows the transmitter to reference the supply common and fully utilize the available supply voltage, a key advantage in scenarios demanding robust signal performance or compatibility with specific control system inputs that leverage a true zero signal.

Find out more about 0-20mA Output Pressure Transmitters to determine which product options and capabilities will best meet your application requirements.

The 0 to 20 milliamp (0-20mA) current loop output remains a robust and reliable signal transmission method in various industrial and research settings for pressure measurement. Specifically, pressure transmitters configured with a 3-wire or 4-wire setup for their 0-20mA output offer distinct advantages in certain applications. Unlike 2-wire loop-powered devices, these transmitters feature a design where the positive voltage supply is entirely separate from the current loop signal wires. This architectural difference is crucial, as it allows the transmitter’s signal conditioning electronics to reference the supply common directly.

One significant benefit of this separation is the ability for the 3-wire and 4-wire 0-20mA output pressure transmitter to leverage the full available supply voltage. This can be particularly advantageous in installations where longer cable runs might introduce voltage drops, or where the sensor’s internal electronics demand higher power for enhanced processing capabilities, diagnostic features, or to drive more complex sensing elements. The dedicated power and signal return paths in these configurations ensure signal integrity and can lead to improved noise immunity, especially in electrically noisy industrial environments.

In a typical 3-wire 0-20mA configuration, you will find a positive supply wire, an output signal wire, and a common negative wire shared by both the supply and the output signal. The 4-wire 0-20mA configuration provides even greater isolation by having separate positive and negative wires for the power supply, and an additional two wires dedicated solely to the 0-20mA current loop signal. This complete separation can be beneficial in preventing ground loop issues and further enhancing signal clarity, making 4-wire transmitters a preferred choice for high-precision measurement tasks or in systems with complex grounding schemes.

Applications where these types of pressure transmitters excel include test benches requiring high accuracy data acquisition, industrial processes with legacy control systems standardized on a 0-20mA input, or specific machinery where the control interface dictates this signal type. For instance, in older manufacturing plants, retrofitting or replacing pressure measurement devices might necessitate compatibility with existing 0-20mA input cards in PLCs or DCS systems. Process engineers and instrument technicians often specify these transmitters when a true zero reading (0mA representing the lowest calibrated pressure) is essential for process control logic or safety interlocks, as opposed to the live zero (4mA) of a 4-20mA signal which indicates a healthy loop.

Product Help

Checklist for 0 to 20 milliamps output pressure transmitter requirements

Define your 0-20mA output signal pressure transmitter requirements using this checklist:

  1. Pressure range?
  2. Output signal? 0-20 milliamps
  3. Accuracy?
  4. Electrical connection?
  5. Process connection?
  6. Process media type?
  7. Temperature range?