Bently Nevada 9200 | Seismoprobe Moving-Coil Velocity Transducer

The Bently Nevada 9200 is a self-powered two-wire Seismoprobe velocity transducer adopting moving-coil mechanical structure, designed to measure absolute casing and bearing housing vibration of rotating machinery. Unlike eddy-current proximity probes for shaft displacement or powered accelerometers, this transducer outputs voltage directly proportional to vibration velocity without external supply power. It can work with 3500/46M, 3300 series monitors and portable vibration analyzers, widely deployed for long-term continuous condition monitoring and periodic field inspection on fans, pumps, compressors and auxiliary rotating equipment. Paired with optional 9513 velocity-displacement converter, it supports conversion of velocity signal into displacement output to match standard TSI system acquisition requirements.

Measurement Object：Absolute vibration of bearing housing, equipment casing and structural components

Working Principle：Passive moving-coil electromagnetic induction, self-powered, no external power supply required

Nominal Sensitivity：20 mV/mm/s (500 mV/in/s) @100 Hz, tolerance ±5%

Frequency Response：Optional lower cutoff 4.5 Hz / 10 Hz / 15 Hz, upper limit 1 kHz (0 ~ -3dB)

Max Vibration Range：25 mm/s (1 in/s) zero-to-peak

Coil Parameters：Coil resistance 1.25 kΩ ±5%; Locked inductance 125 mH typical

Transverse Sensitivity：≤10% of axial sensitivity

Shock Resistance：50 g peak along transverse non-sensitive axis

Operating Temperature：-29 ℃ ~ +121 ℃ (-20 ℉ ~ +250 ℉)

Cable Limit：Maximum transmission distance 305 m (1000 ft) with matched shielded cable

Connector Option：Top MIL 2-pin connector / integrated fixed cable version

Certification：Suitable for general industrial hazardous area matching requirements

2. Standard Ordering Code Structure & Configuration Definition

Complete Order Format：9200-AA-BB-CC-DD-EE

AA Code: Low Cutoff Frequency

BB Code: Mounting Orientation

CC Code: Connector / Cable Type

DD Code: Cable Armour & Protection

EE Code: Special Option & Revision

Matching Accessories List

3. Core Product Advantages

The 9200 passive moving-coil velocity transducer features unique self-powered passive design, eliminating risk of sensor failure caused by loss of excitation power compared with powered accelerometers. Moving-coil mechanical construction delivers lower sensitivity to impact pulse interference, acquiring stable continuous casing vibration waveform on equipment with frequent load fluctuation. Two-wire simple wiring layout reduces field cable engineering workload, and it supports both fixed online monitoring and temporary portable measurement. Multiple cutoff frequency selections adapt to low-speed water turbines, medium-speed pumps and high-speed blowers. Stainless steel hermetic housing offers reliable corrosion resistance, suitable for humid, dusty general industrial environments. It can be directly interfaced with Bently Nevada 3500/46M seismic monitor module without complicated signal conditioning, perfectly matching existing 3500 TSI machinery protection system architecture.

4. Industrial Application Scenarios

The 9200 transducer focuses on casing absolute vibration monitoring of auxiliary rotating machinery, widely used across power, petrochemical, water treatment and metallurgical industries. In thermal power plants, it monitors casing vibration of induced draft fans, forced draft fans, circulating water pumps and auxiliary turbines. Within petrochemical plants, it serves centrifugal pump, screw compressor and cooling fan condition monitoring. It is also adopted in water supply pumping stations, large ventilation equipment and waste heat recovery unit auxiliary machinery. It is commonly used for equipment early fault warning such as bearing wear, structural loosening and rotor imbalance, forming a complete monitoring solution matched with the 3500 series rack protection system.

5. Model Differentiation Note (9200 VS 74712)

74712 is the high-temperature variant of the Seismoprobe series, operating range -29 ℃ ~ +204 ℃; 9200 is standard temperature version up to +121 ℃. Their electrical parameters, sensitivity and frequency characteristics are consistent, only differing in high-temperature material configuration for casing internal components.