Yokogawa AMM31 ADMAG Series Magnetic Flow Converter

Configured for converting signals from magnetic flow tubes into standardized outputs within process automation networks, the Yokogawa AMM31, also cataloged as the AMM31 Magnetic Flow Converter, provides direct physical/electrical execution.

Hardware Specifications

Process Control & DCS Instrumentation Properties

The module utilizes a 4-20 mA HART loop protocol alongside the proprietary BRAIN communication layer to interface directly with distributed control system (DCS) architectures. To preserve signal integrity across long-distance topologies up to 2 km, the hardware maintains independent channel-to-channel isolation parameters between the primary flow tube excitation circuit and the analog/pulse output terminals. Signal processing functions leverage dual-frequency excitation techniques to suppress slurry noise and fluid hydrodynamic variations, executing real-time digital filtering without introducing phase lag into the 4-20 mA control loop.

Frequently Asked Questions

Q: What are the specific load resistance boundaries for establishing digital communication with the AMM31?

A: For BRAIN protocol communication, the loop must maintain a load resistance between 250 Ohm and 600 Ohm. For HART protocol configuration, the required loop resistance range is 230 Ohm and 600 Ohm.

Q: How does the unit store calibration and configuration constants during a total power disruption?

A: The device writes all operational parameters, flow tube constants, and multi-range settings directly to an internal EEPROM. This non-volatile storage method eliminates the need for lithium backup batteries and prevents data corruption during prolonged power outages.

Field Installation Guidelines

• Grounding Infrastructure: Connect the module to an independent instrument ground. The grounding resistance must not exceed 100 Ohm for standard operations. If the hardware variant includes the integrated surge arrestor function, the grounding resistance must be maintained at 10 Ohm or less to safely dissipate transient overvoltages.
• Signal Cable Routing: Field wiring between the magnetic flow tube and the AMM31 converter must use dedicated PVC-sheathed control cables. Do not route these signal cables in parallel or within the same conduit as high-voltage AC power lines to avoid electromagnetic cross-talk. The maximum physical cable length must never exceed the 2 km specification.
• Enclosure Maintenance: To preserve the NEMA 4 equivalent environmental seal, verify that all conduit entries use appropriate weather-tight seals or glands. Ensure the aluminum alloy housing cover is fully threaded and seated against its gasket to inhibit moisture ingress in high-humidity processing zones.