Product Overview

The Emerson EPRO PR9268/20 functions as a high-integrity electrodynamic velocity sensor (EDS) for monitoring absolute case vibration. Unlike relative proximity probes, this sensor mounts directly to the machine housing or bearing pedestal to capture the seismic vibration of the structure itself. It utilizes a passive electrodynamic measurement principle, generating a self-sufficient voltage signal proportional to the vibration velocity. We supply this unit as 100% Brand New and Factory Sealed, ensuring critical protection for high-speed rotating machinery in power plants and petrochemical facilities.

Technical Specifications

The PR9268/20 provides reliable signal acquisition across a broad industrial frequency spectrum.

Engineering Advantages

• Passive Power Architecture: The PR9268/20 requires no external excitation voltage. This design eliminates potential noise interference from power supply loops and ensures the sensor remains operational even during local power infrastructure failures.

• Low-Frequency Accuracy: With a natural frequency of approximately 4.5 Hz, this sensor excels at detecting low-speed mechanical imbalances and misalignments that standard high-frequency accelerometers often overlook.

• Optimized Signal Strength: The 20 mV/mm/s sensitivity provides a robust output signal. This high signal-to-noise ratio allows for clean data transmission even in electrically "noisy" environments near large motor drives or generators.

• Compact Installation Footprint: The 2-meter integrated cable facilitates installation in cramped machinery spaces or internal bearing housings. This fixed-length design minimizes the need for excess cable management and reduces the number of potential failure points at connection terminals.

FAQs

• Does the PR9268/20 measure shaft displacement?

  No. The PR9268/20 measures absolute case vibration. It tracks the movement of the bearing housing or machine casing. For a complete machinery protection profile according to API 670, you should pair this sensor with an eddy current proximity probe (like the PR6423) to measure the relative movement of the shaft inside the bearing.

• Is there a specific mounting orientation for the PR9268/20?

  Yes. Electrodynamic sensors contain an internal mass suspended by springs. You must mount the sensor according to its specific design axis (vertical or horizontal). Mounting the sensor at an incorrect angle will shift the internal mass away from its center, causing signal distortion or premature mechanical wear.

• Can I replace the 2-meter cable if it is damaged?

  The PR9268/20 features a fixed, integrated cable. We do not recommend field-splicing or replacing the cable, as this can compromise the IP rating and electrical shielding. If your installation requires a longer distance, we suggest terminating the 2m lead into a high-quality junction box before extending the run.

• Does this sensor require a signal converter?

  While the PR9268/20 generates a raw voltage signal, it typically connects to an Emerson MMS6000 or AMS6500 rack module. These modules perform the necessary signal integration (if you require displacement readings) and apply the alarm/trip logic for machinery protection.