ABB

1.Main Functions

Millivolt‑level weak signal acquisition and conditioning: Specifically designed for low‑level millivolt output from thermocouples and other low‑mV transducers. It amplifies tiny raw field signals, performs impedance matching, multi‑stage low‑pass filtering, and converts weak millivolt inputs into standardized analog levels compatible with INFI‑90 back‑plane bus.

PS 868 Millivolt‑Input Signal Conditioning Module

Complete galvanic isolation: Provides electrical separation between field sensor circuits and DCS internal circuits. It suppresses ground‑loop currents, common‑mode noise and transient surge interference induced by long field cables, protecting downstream DCS I/O and controller hardware.
Precision zero‑point and span hardware calibration: Equipped with high‑sensitivity on‑board potentiometers. Field technicians can fine‑tune zero offset and full‑scale span parameters to compensate for thermocouple drift and match different thermocouple type output characteristics.
Low‑level signal interface adaptation: Acts as a dedicated signal bridge between millivolt‑type field instrumentation and INFI‑90 rack back‑plane bus. It converts hard‑to‑process tiny sensor outputs into readable signals for subsequent DCS processing modules.More products: www.plcva.com
Optimized noise suppression for micro‑voltage signals: Implements dedicated analog filtering circuits for feeble millivolt signals. It effectively rejects industrial high‑frequency EMI interference and reduces signal jitter, delivering stable temperature‑related measurement values for control loops.
Cold‑junction compensation support: Works cooperatively with external cold‑junction compensation devices for thermocouple measurement, improving temperature‑reading accuracy for thermal process points.

PS 868 Millivolt‑Input Signal Conditioning Module

Legacy INFI‑90 DCS cabinet deployment: Installed inside standard ABB Bailey INFI‑90 racks, arranged between field thermocouple wiring and main DCS I/O processing boards.
Industrial temperature measurement: Primary for processing millivolt signals from various thermocouple sensors, widely used to monitor furnace, reactor, boiler and pipeline temperature points.plcva.com

PS 868 Millivolt‑Input Signal Conditioning Module

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.
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.