Description

The BENTLY 125840-02 is a high-sensitivity Seismic Accelerometer from Baker Hughes’ Bently Nevada portfolio, engineered for precision vibration monitoring on low-speed machinery and structural assets. Designed to detect subtle mechanical defects in non-rotating equipment, this rugged sensor converts acceleration forces (g) into standardized 4-20mA or voltage signals for predictive maintenance systems. The 125840-02 operates on the piezoelectric principle with integrated signal conditioning, delivering flat frequency response from 2 Hz to 10 kHz – ideal for capturing early-stage bearing degradation, resonance issues, or loose component vibrations missed by conventional proximity probes. Housed in a corrosion-resistant stainless steel casing with integral mounting threads, it withstands harsh environments like offshore platforms, pulp mills, and power generation facilities. As a critical component of Bently Nevada’s System 1™ architecture, the BENTLY 125840-02 transforms structural vibration data into actionable intelligence, enabling maintenance teams to prevent catastrophic failures and optimize asset reliability in slow-rotating (<600>

BENTLY 125840-02

Technical Specifications

Main Features and Advantages

Ultra-Low Frequency Capability: Unlike conventional accelerometers, the 125840-02 maintains accuracy down to 2 Hz – critical for monitoring gearbox foundations, reciprocating compressors, and cooling tower structures where sub-10Hz vibrations indicate misalignment or resonance.

Intrinsic Safety Certification: With ATEX/IECEx Ex ia approval, the sensor operates safely in Zone 0 hazardous areas (petrochemical refineries, gas processing) without external barriers.

Environmental Robustness: The hermetic stainless steel weld eliminates O-ring failure points, while the IP68 rating ensures reliable performance in washdown areas or submerged applications. Integral cable strain relief prevents moisture ingress at the connection point.

Plug-and-Play Integration: Pre-calibrated sensitivity simplifies installation with Bently Nevada 1900/65A transmitters or third-party PLCs. Linear phase response enables accurate time waveform capture for advanced diagnostics.

High Noise Immunity: Shielding and differential output reject EMI from VFDs and welding equipment, ensuring signal fidelity in electrically noisy environments.

Application Field

The BENTLY 125840-02 excels in monitoring slow-speed and structural assets:

Power Generation: Detecting foundation cracks in turbine pedestals, loose stator core vibrations, and cooling water pump resonance.

Oil & Gas: Monitoring reciprocating compressor skid vibrations, pipeline pumping station structures, and offshore platform leg resonances.

Pulp & Paper: Diagnosing felt roll bearing defects in paper machines and gearbox housing vibrations in chip conveyors.

Mining: Identifying structural fatigue in crusher foundations and abnormal vibrations on slurry pump bases.

Water Treatment: Detecting impeller imbalance in vertical turbine pumps and resonance in aeration blower concrete pads.
In all applications, the 125840-02 provides early warning of mechanical looseness, concrete degradation, or resonance issues before they propagate to catastrophic failure.

BENTLY 125840-02

Related Products

1900/65A Vibration Transmitter: Converts 125840-02‘s raw signal into 4-20mA with buffered acceleration/velocity outputs.

3300/25 Proximitor® System: For shaft relative vibration monitoring (complements seismic data).

3500/42M Seismic Monitor: Dedicated rack module processing 125840-02 inputs for machinery protection.

125840-01: Lower-sensitivity variant (50 mV/g) for high-g shock monitoring.

125840-03: High-temperature version rated to +260°C for furnace applications.

TK81 Calibration Exciter: Validates 125840-02 sensitivity and frequency response.

System 1™ Software: Analyzes vibration trends from 125840-02 networks.

Installation and Maintenance

Pre-installation preparation: Clean mounting surface to ISO 8501-1 Sa2.5 standard. Verify flatness (<0>BENTLY TG-11 mounting grease on threads. Route cable away from high-voltage lines (>1m separation). For hazardous areas, confirm loop certification matches control system barriers.

Maintenance recommendations: Quarterly inspect cable jacket for cuts/abrasions. Annually verify calibration via TK81 exciter at 10 Hz/1g and 100 Hz/5g (±8% tolerance). Never disassemble the hermetic weld. Replace the 125840-02 if baseline sensitivity shifts >10% or if impact damage occurs.