Bently Nevada 990 Series Modules - 990-10-XX-01-05 MOD:165353-01

Technical Dossier

Product Details And Specifications

Bently Nevada 990 Series Technical Notes

The Bently Nevada 990 Series vibration transmitter is a field-mounted, 4–20 mA output transducer system engineered for continuous machinery protection in heavy industrial environments. Deployed across petrochemical complexes, nuclear power stations, offshore platforms, LNG terminals, and crude oil refineries, the 990 Series occupies a critical position in rotating equipment monitoring infrastructure worldwide. It interfaces directly with proximity probes (typically 3300 XL series) and converts raw eddy-current displacement signals into industry-standard analog outputs compatible with DCS, PLC, and standalone monitoring systems. Its DIN-rail and panel-mount form factors, combined with a wide supply voltage tolerance (18–30 VDC), make it a default specification item in API 670-compliant machinery protection systems for turbines, compressors, pumps, and gearboxes.

The Evolution of 990 Series Architecture

The 990 Series was introduced as a successor to earlier Bently Nevada field transmitter designs that required rack-mounted signal conditioning. The core architectural shift was relocating signal processing to the field instrument itself, eliminating the need for dedicated monitor rack slots for basic 4–20 mA output applications. Early variants (990-05-XX-01-05) supported standard 200 mV/mil (7.87 mV/µm) proximity probe sensitivity with fixed gap voltage windows. Subsequent revisions introduced configurable full-scale ranges (5–100 mil pp), selectable AC (dynamic) or DC (gap) output modes, and ATEX/IECEx hazardous area certifications for Zone 1/Zone 2 installations. The MOD suffix (e.g., MOD:165353-01) denotes factory-applied hardware modifications that alter default configuration parameters—commonly used to meet site-specific API 670 alarm setpoints or to adapt output scaling for legacy DCS input cards. As of the mid-2010s, the 990 Series entered the mature/end-of-active-production phase. Bently Nevada (a Baker Hughes company) has transitioned new installations toward the 3500 Series rack-based system and the Orbit 60 platform. However, the installed base of 990 Series transmitters in operating plants remains substantial, and replacement demand for maintenance, turnaround, and life extension projects continues globally.

990 Series Full Catalog & Functionalities (SKU List)

The following SKUs represent verified, commonly stocked models within the Bently Nevada 990 Series. Models are organized by output mode and area classification.

Standard (Non-Hazardous Area) — AC Vibration Output:

• 990-05-XX-01-05: 4–20 mA, AC vibration, 5 mil full scale, standard probe input
• 990-10-XX-01-05: 4–20 mA, AC vibration, 10 mil full scale, standard probe input
• 990-10-XX-01-05 MOD:165353-01: 4–20 mA, AC vibration, 10 mil FS, factory-modified output scaling
• 990-25-XX-01-05: 4–20 mA, AC vibration, 25 mil full scale, standard probe input
• 990-50-XX-01-05: 4–20 mA, AC vibration, 50 mil full scale, standard probe input
• 990-100-XX-01-05: 4–20 mA, AC vibration, 100 mil full scale, standard probe input

Standard (Non-Hazardous Area) — DC Gap Output:

• 990-05-XX-02-05: 4–20 mA, DC gap/position output, 5 mil full scale
• 990-10-XX-02-05: 4–20 mA, DC gap/position output, 10 mil full scale
• 990-25-XX-02-05: 4–20 mA, DC gap/position output, 25 mil full scale
• 990-50-XX-02-05: 4–20 mA, DC gap/position output, 50 mil full scale

Hazardous Area (ATEX/IECEx Certified) — AC Vibration Output:

• 990-05-XX-01-CN: 4–20 mA, AC vibration, 5 mil FS, ATEX Zone 1 certified
• 990-10-XX-01-CN: 4–20 mA, AC vibration, 10 mil FS, ATEX Zone 1 certified
• 990-25-XX-01-CN: 4–20 mA, AC vibration, 25 mil FS, ATEX Zone 1 certified
• 990-05-XX-02-CN: 4–20 mA, DC gap output, 5 mil FS, ATEX Zone 1 certified
• 990-10-XX-02-CN: 4–20 mA, DC gap output, 10 mil FS, ATEX Zone 1 certified
• 990-25-XX-02-CN: 4–20 mA, DC gap output, 25 mil FS, ATEX Zone 1 certified

Note: The "XX" position in the part number denotes the cable length code (e.g., 01 = 1 m, 05 = 5 m, 09 = 9 m). Specify cable length when ordering.

Quality Control for the 990 Series Range

Each 990 Series unit processed by DriveKNMS undergoes a structured verification protocol aligned with Bently Nevada factory acceptance criteria. Testing includes: supply voltage sweep (18–30 VDC) with output linearity verification across the full 4–20 mA range; proximity probe simulator input at calibrated gap voltages (−2 VDC to −18 VDC) to confirm sensitivity coefficient accuracy (200 mV/mil ±1%); AC vibration channel frequency response check (10 Hz–1 kHz); DC gap channel static accuracy verification; and output load compliance test (0–600 Ω). For ATEX-certified variants, enclosure integrity and label compliance are inspected against IECEx documentation. All units are issued a test certificate with recorded measurement data. Units failing any parameter are quarantined and not offered for sale.