EPRO PR9268/302-100 Vibration Velocity Sensors

The Emerson PR9268/302-100, also cataloged as the PR9268 Electrodynamic Velocity Sensor, operates as a dedicated hardware component for absolute seismic vibration measurement within turbomachinery protection platforms.

Suffix Breakdown & Model Matrix

• PR9268/01x-x00: Omni-directional orientation version; sensitivity 17.5 mV/mm/s; frequency range 14 to 1000 Hz; temperature range -20 to +100 deg C.
• PR9268/20x-x00: Vertical orientation (+/- 60 deg); sensitivity 28.5 mV/mm/s; frequency range 4 to 1000 Hz; protection class IP55.
• PR9268/30x-x00 (Includes PR9268/302-100): Horizontal orientation (+/- 30 deg); sensitivity 28.5 mV/mm/s; frequency range 4 to 1000 Hz; protection class IP55.
• PR9268/60x-000: High-temp vertical version; sensitivity 22.0 mV/mm/s; frequency range 10 to 1000 Hz; temperature range -20 to +200 deg C.
• PR9268/70x-000: High-temp horizontal version; sensitivity 22.0 mV/mm/s; frequency range 10 to 1000 Hz; temperature range -20 to +200 deg C.

Hardware Specifications

Rotor Dynamics & Cross-Talk Suppression

The electrodynamic seismic system generates output signals proportional to absolute velocity without active power supply requirements. Proper physical alignment along the horizontal shaft plane is required during mounting to suppress cross-talk and preserve transient response across low-frequency rotor dynamic events.

Frequently Asked Questions

Q: What mounting angle tolerance applies to the PR9268/302-100 execution?

A: The horizontal execution allows an alignment tolerance of +/- 30 deg from the true horizontal plane.

Q: Does the sensor require an external power supply to output vibration velocity?

A: No, the sensor uses a moving coil in a permanent magnetic field to self-generate voltage proportional to mechanical velocity.

Field Installation Guidelines

• Ensure a minimum of 5 full threads of engagement when securing mounting studs into the bearing housing.
• Route sensor cabling through grounded metal conduit away from high-voltage motor leads and variable frequency drive (VFD) outputs to prevent high-frequency interference.
• Verify that signal cable shielding is grounded at a single point (typically at the cabinet barrier/rack terminal) to eliminate ground loops.
• Align the physical mounting axis within the allowable +/- 30 deg horizontal window before final torque application.