ABB

1.Main Functions

Dual‑type weak‑signal acquisition and conditioning: Accepts two categories of field sensor signals: RTD resistance‑based temperature signals and millivolt‑level thermocouple signals. It completes resistance‑to‑voltage conversion, signal amplification, impedance matching and multi‑stage low‑pass filtering, and converts raw field weak signals into standardized analog levels compatible with INFI‑90 back‑plane bus.More products: www.plcva.com
Complete galvanic isolation: Provides full electrical separation between field sensor circuits and DCS internal circuits. It suppresses ground‑loop currents, common‑mode noise and transient surge interference caused by long‑distance field cables, protecting downstream DCS I/O boards and controller hardware.

PS 873B RTD & Millivolt Dual‑Input Signal Conditioning Module

Precision hardware calibration: Equipped with high‑resolution on‑board potentiometers. Field technicians can fine‑tune zero offset and full‑scale span to compensate for sensor drift and match different RTD and thermocouple characteristic curves.
Built‑in cold‑junction compensation support: Supports cold‑junction compensation for thermocouple measurement. It cooperates with system temperature reference to improve temperature‑reading accuracy for thermal process measuring points.
Dedicated noise suppression for low‑level signals: Optimized analog filtering circuit for feeble millivolt and resistance‑based signals. It effectively filters industrial EMI interference and reduces signal jitter, delivering stable temperature measurement values for control loops.
Multi‑sensor interface adaptation: Acts as a signal bridge between field temperature instrumentation and INFI‑90 rack back‑plane bus. It converts diverse RTD and thermocouple outputs into recognizable signals for subsequent DCS processing modules.plcva.com

PS 873B RTD & Millivolt Dual‑Input Signal Conditioning Module

Legacy INFI‑90 DCS cabinet deployment: Installed inside standard ABB Bailey INFI‑90 racks, arranged between field temperature‑sensor wiring and main DCS I/O processing boards.
Multi‑type industrial temperature measurement: Processes signals from RTD (Pt100 etc.) and multiple‑type thermocouples. Widely used for monitoring boiler, reactor, furnace, pipeline and heat‑exchanger temperature measuring points.
Heavy‑EMI heavy‑industry sites: Deployed in thermal power plants, chemical complexes, metallurgical plants, pulp‑and‑paper mills with long field wiring and severe electromagnetic disturbances.

PS 873B RTD & Millivolt Dual‑Input Signal Conditioning Module

Plant maintenance, spare‑part replacement and retrofitting: Serves as critical spare replacement component for aging INFI‑90 control racks, applied in equipment overhaul, on‑site repair and legacy‑system modernization projects.
Temperature‑related closed‑loop regulation: Supplies conditioned stable temperature‑process‑variable signals to DCS PID control algorithms, supporting reliable automatic temperature control for key production loops.