Low-Power, High-Integration Two-Wire Electromagnetic Flowmeter

A two-wire electromagnetic flowmeter refers to an electromagnetic flowmeter that simultaneously accomplishes power supply and signal transmission using only two wires.

• Extremely low wiring cost and easy installation: Save a large amount of cable and construction costs. The traditional four-wire system requires two power lines and two signal lines, while the two-wire system only needs a pair of twisted wires, making it especially suitable for long-distance and multi-point distribution scenarios.
• Inherent safety and explosion-proof advantage: As the entire circuit's energy is limited to 4-20mA and the voltage is usually at a low level of ≤24V DC, it is very easy to achieve Intrinsic Safety (Ex ia) certification, making it an ideal choice for hazardous areas such as chemical and petroleum industries.
• Strong anti-interference ability: Current signal transmission is not sensitive to changes in line resistance and is less affected by electromagnetic interference, making it suitable for long-distance transmission.
• "Live zero point" for easy diagnosis: The "live zero point" at 4mA can clearly distinguish between "instrument failure/power off (0mA)" and "true zero flow (4mA)", facilitating remote diagnosis.
• Easy system integration: Seamless compatibility with current mainstream DCS/PLC control systems (whose analog input cards generally support two-wire 4-20mA power supply), without the need for additional power distribution.

1. Hazardous areas in oil, chemical, natural gas, etc.: tank farm metering, process pipelines, flammable and explosive media.
2. Water treatment and municipal water networks: distributed water supply/drainage monitoring points, remote transmission water meters.
3. Energy management and building automation: central air conditioning cold/hot water metering, district heating metering.
4. Equipment matching and OEM: integrated into complete sets of equipment (such as water treatment units, chemical equipment).
5. Newly built digital factories: all plant instrument signals uniformly adopt two-wire 4-20mA standard.

Two-wire electromagnetic flowmeters are a successful example of the development of electromagnetic flowmeter technology towards "low power consumption, high integration, and intrinsic safety". It is not merely a change in wiring method, but also an innovation in system design concept.