The Model 4104XT or 4104WT Probe Interface Module (PIM) is the front end probe interface for use with CORROSOMETER® or CORROTEMP® CORROSOMETER® probes in dedicated continous on-line ICMS™ corrosion monitoring systems. An explosion proof enclosure allows the unit to be mounted in a electrically hazardous area of the plant as close to the probes as possible optimizing performance and minimizing cabling costs. Integral safety barriers permit conventional cabling connections to the probes without explosion proof conduit. This cost-effective unit interfaces from 1 to 4 CORROSOMETER® or CORROTEMP® CORROSOMETER® probes to the central Corrosion Monitoring Computer via a low-cost RS-485 cable. Up to 32 PIMs (128 probes) can be connected over the RS-485 communication network.