Bently Nevada 990-05-XX-03-05 2-Wire Vibration Transmitter
Overview
The Bently Nevada 990-05-XX-03-05 is a 2-wire vibration transmitter from the Bently Nevada 990 series, a compact transmitter that measures shaft or housing vibration and outputs a proportional 4 to 20 mA signal for the machinery control system. The 990 series is designed primarily for OEMs of centrifugal air compressors and for small pumps, motors and fans where a simple 4 to 20 mA vibration signal is preferred instead of a full monitoring rack. This configuration carries the 0-5 mils pp full-scale option with DIN and bulkhead mounting provisions and a complete hazardous area approval set.
The 990 series has been applied across several decades of OEM and retrofit installations, which is why legacy part number lists sometimes carry an XX digit in the system length position. On those records, the length option was left open at the time the machine data sheet was prepared and should be confirmed from the installed cable before a replacement transmitter is ordered. The transmitter electronics are identical across the series; only the full-scale, length, mounting and approval options change between configurations.
Engineering and Design
The 990 transmitter accepts the signal from a probe or velocity sensor, conditions it and drives a 4 to 20 mAdc loop current proportional to the vibration full-scale value. The 05 full-scale option sets the span at 0-5 mils peak-to-peak (0-125 micrometres), and the 2-wire loop connection carries both power and signal, with the loop powered from a 28 V supply. A buffered gap voltage output is also provided for diagnostics, and the loop output can be connected directly to PLC analog inputs or DCS cards.
The 03 mounting option fits the transmitter with DIN rail clips and screws, allowing either type of installation in the panel or junction box. In a typical retrofit, the existing probe cable is connected to the transmitter input, the loop is wired in series with the 250 ohm resistor if a voltage signal is required, and the full-scale value is confirmed against the calibration label before commissioning. The XX system length digit in this part number records a legacy option; the correct system length should be confirmed with the supplier before ordering.
Field checks on the 990 consist of verifying the loop current against a known vibration level and recording the gap voltage at the buffered output. The loop supply should be confirmed at 28 V and the total loop resistance kept within the transmitter rating so the output reaches its full 20 mA value. Because the transmitter is a single-point device, a failed unit is replaced complete with its probe assembly, and the new pair is verified against the same full-scale option. The live 4 to 20 mA value is compared with a portable meter during the annual shutdown to confirm loop calibration.
Key Features
- 2-wire 4 to 20 mA output proportional to vibration
- 0-5 mils pp (0-125 micrometres) full-scale option
- Accepts probe input with buffered gap voltage output
- Loop powered from 28 V supply
- DIN rail clips and screws mounting option
- CSA Division 2, ATEX Zone 0 and Zone 2 approvals option
- Compact OEM-friendly package for small machinery
Applications
The 990 series is applied to centrifugal air compressors, small pumps, motors, fans and blowers where the control system needs a live vibration value rather than alarm relays. It is used on packaged and skid-mounted OEM equipment and as a simple upgrade path from vibration switches on balance-of-plant machinery.
Specifications
| Part number | 990-05-XX-03-05 |
| Series | 990 2-wire vibration transmitter |
| Full-scale | 05 (0-5 mils pp, 0-125 micrometres) |
| Output | 4 to 20 mAdc proportional |
| System length | XX (legacy option, confirm before ordering) |
| Mounting | 03 (DIN rail clips and screws) |
| Approvals | 05 option (CSA Div 2, ATEX Zone 0, Zone 2, ABS) |
| Loop supply | 28 V |
Why Seven Star LLC
Seven Star LLC supplies verified Bently Nevada 990 series transmitters and transducers to OEM and maintenance programmes across Oman and the GCC. Every 990 is checked against the complete part number, full-scale value and mounting option before your order is confirmed, and our team verifies the loop supply and cabling for your control system.
Technical Specifications
The Bently Nevada 990-05-XX-03-05 is a loop-powered 2-wire vibration transmitter that converts a proximity-probe vibration signal into a standard 4–20mA analog output for direct DCS/PLC integration — no separate monitoring rack is required for basic overall-vibration trending. The part number encodes the configuration: the first “05” specifies a 0–5 mils peak-to-peak (0–125µm pp) full-scale measurement range, “03” specifies DIN-clip or screw mounting, and the final “05” specifies CSA Division 2, ATEX Zone 0/2, plus ABS maritime certification.
The transmitter outputs 4–20mA over a 2-wire loop with an accuracy of ±1.5% of full scale, powered from a 12–35V DC loop supply, and covers a frequency response of 5Hz to 6,000Hz (+0/-3dB). The transmitter itself is rated for -35°C to +85°C operation, while the connected probe is rated to -52°C to +177°C, and the unit tolerates up to 100% condensing humidity provided it is not submerged.
Applications
This transmitter is used for overall vibration monitoring on machinery that does not warrant a full multi-channel protection rack — centrifugal air compressors, small pumps, motors, and fans — giving plants a simple 4–20mA trend signal into an existing control system for balance-of-plant rotating equipment, while critical turbomachinery trains typically use a full Bently Nevada 3300/3500 monitoring system instead.
Why Seven Star LLC
Seven Star LLC supplies genuine Bently Nevada (Baker Hughes) 990-series vibration transmitters to power generation, oil & gas, and petrochemical customers across Oman and the wider GCC, and confirms the exact full-scale range and certification suffix required for the customer’s machine and hazardous-area classification before confirming an order.
Request a Quote for Bently Nevada 990-05-XX-03-05 2-Wire Vibration Transmitter
Submit a formal inquiry through our RFQ page with the transmitter part number 990-05-XX-03-05, your vibration full-scale requirement and loop supply voltage. We will confirm the correct 990 configuration and respond with a formal quotation. | Inquiry Form
Related Products
Bently Nevada, a division of Baker Hughes, is a global leader in asset condition monitoring and protection technologies. For over six decades, the company has set the industry standard in machinery diagnostics, vibration analysis, and predictive maintenance solutions.
Its advanced systems and sensors are designed to ensure maximum equipment uptime, safety, and efficiency across power generation, oil & gas, and industrial manufacturing sectors. From vibration probes and monitoring racks to software platforms like System 1, Bently Nevada products enable real-time insight and data-driven decision-making.
Seven Star LLC supplies genuine Bently Nevada equipment, sensors, and monitoring solutions to clients across the Middle East, providing trusted reliability, expert support, and seamless integration for modern industrial operations.
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