Epro PR9268/302 Seismic Velocity Vibration Sensor

Product Overview

The PR9268/302 is a seismic velocity vibration sensor developed by Epro (Emerson) for direct measurement of absolute bearing vibration in rotating machinery. It operates on electrodynamic principles, converting mechanical motion at the bearing housing into an electrical signal proportional to vibration velocity.

This sensor is commonly used as a primary input device in machinery protection and condition monitoring systems for turbines, compressors, pumps, and industrial fans.

Measurement Principle

The device functions as a self-generating velocity transducer. Internal coil and magnetic structures produce a voltage signal proportional to housing vibration velocity. Because it is seismic in design, it measures absolute vibration at the mounting point rather than shaft relative motion.

This makes it suitable for applications where bearing housing condition is the primary diagnostic parameter.

Technical Specifications

Model: PR9268/302
Manufacturer: Epro (Emerson)
Product Type: Seismic Vibration Sensor / Velocity Transducer

Measurement Type: Absolute bearing vibration (velocity)
Operating Principle: Electrodynamic induction

Frequency Response: Approximately 10 Hz to 1,000 Hz (typical for PR9268 series)
Output Signal: Analog voltage proportional to vibration velocity

Sensitivity: Factory-calibrated depending on configuration variant
Shock Resistance: Up to 20 g

Mounting Method: Rigid installation on bearing housing or machine frame
Connector Type: Industrial-grade connector (variant dependent)

Operating Environment:

• High vibration resistance

• High temperature industrial conditions

• EMI-resistant design for industrial environments

System Compatibility:

• Compatible with Epro monitoring modules such as MMS3120 and MMA3120 series

• Direct integration into vibration protection systems

Key Engineering Characteristics

• Self-powered electrodynamic measurement principle (no external excitation required)

• Direct measurement of bearing housing vibration for reliable condition assessment

• Stable output signal across wide operational frequency range

• Rugged construction for continuous industrial operation

• Suitable for long-term installation in harsh mechanical environments

• Designed for integration with standardized vibration monitoring platforms

Application Areas

• Steam and gas turbines

• Hydro power generation systems

• Centrifugal and reciprocating compressors

• Industrial pump and motor systems

• Cooling fans and auxiliary rotating equipment

• Condition monitoring and predictive maintenance systems

FAQ

What type of vibration does this sensor measure?
It measures absolute vibration at the bearing housing using velocity-based seismic sensing.

Does it require external power?
No, it is a self-generating electrodynamic sensor.

Is it suitable for shaft vibration measurement?
No, it is designed for bearing housing vibration rather than shaft-relative displacement.

What systems can it connect to?
It is compatible with Epro MMS and MMA monitoring modules.

Can it operate in harsh environments?
Yes, it is designed for high vibration, temperature, and industrial EMI conditions.