The Bently Nevada 3500/72M Recip Rod Position Monitor is a four-channel monitoring module designed to measure and analyze piston rod position and drop in reciprocating compressors.
It provides continuous protection and diagnostic information by acquiring signals from eddy current proximity probes, conditioning the signals, and comparing them against user-programmable alarm setpoints.
The monitor supports configuration through the 3500 Rack Configuration Software and integrates seamlessly into the 3500 Machinery Protection System and System 1® condition monitoring platform.

Technical Specifications

Inputs

Outputs

Measurement Performance

Frequency Response

Physical Characteristics

Key Features

Multi-Channel Design

Supports up to four monitoring channels, allowing simultaneous observation of multiple pump rods.
Channels are configured in pairs and can be programmed to perform up to two functions simultaneously, including:

Piston rod position measurement

Piston rod drop measurement

Ultra-high-pressure compressor monitoring

Comprehensive Measurement Parameters

Provides a wide range of dynamic and static parameters, including:

Piston rod displacement

Average and instantaneous probe clearance

Position angle

Crank angle

Peak-to-peak amplitude

1X, 2X, and non-1X amplitudes

User-Programmable Alarm Functions

Integrated Form C relay outputs allow configuration of alerts for various conditions, including:

High or low piston position

Excessive vibration

Signal loss or sensor fault

System Compatibility and Communication

Fully compatible with other modules within the Bently Nevada 3500 Framework

Communicates waveform and diagnostic data through the 3500 Transient Data Interface (TDI) module

Data accessible via System 1® software for advanced machinery diagnostics and predictive maintenance