Product Description

The AMM22TJ is a high-density thermocouple input multiplexer designed for Yokogawa Distributed Control Systems (DCS), including CENTUM CS and CENTUM VP platforms. The module supports 16 thermocouple input channels, converting low-level millivolt thermal signals into accurate digital values for reliable temperature monitoring and control.

To ensure measurement integrity in harsh industrial environments, the AMM22TJ integrates internal Cold Junction Compensation (CJC), maintaining accuracy despite variations in terminal temperature. The module also incorporates comprehensive diagnostics, including open-circuit (burnout) detection and short-circuit protection, safeguarding both the field wiring and internal electronics. Its compact form factor enables efficient installation in standard I/O nests, making it well suited for applications ranging from cryogenic systems to high-temperature furnace operations.

Technical Specifications

Application Scenarios

• Thermal Processing Equipment
  Multi-zone temperature monitoring in industrial ovens, kilns, and furnaces using high-temperature thermocouples (Type R, S, B).

• Safety Instrumented Applications
  Redundant temperature feedback in chemical reactors for early detection of abnormal thermal conditions.

• HVAC & Utility Systems
  Centralized monitoring of boilers, heat exchangers, and plant-wide thermal utilities.

Product FAQ

Q: Does the AMM22TJ require an external power supply?
A: Yes. The module operates on a 24 V DC supply, typically provided through the Yokogawa I/O nest backplane or associated terminal wiring.

Q: Can the AMM22TJ detect broken thermocouple wiring?
A: Yes. The built-in open-circuit (burnout) detection identifies thermocouple disconnection or failure and reports a diagnostic alarm to the CENTUM CS / VP operator station.