Bently Nevada 990-04-70-01-00 2-Wire Vibration Transmitter
Overview
The Bently Nevada 990-04-70-01-00 is a 2-wire vibration transmitter from the 990 series, providing a proportional 4 to 20 mA vibration signal to the machinery control system. The 990 series is intended primarily for OEMs of centrifugal air compressors and for small pumps, motors and fans that prefer a simple analog vibration signal instead of a monitoring rack. This configuration specifies the 0-4 mils peak-to-peak full-scale option, a 7.0 metre system length, DIN rail clip mounting and no agency approval option.
The 0-4 mils full-scale option covers the vibration range of most small and medium machines, from packaged compressors to balance-of-plant pumps, and the 4 to 20 mA output gives the control system a live indication that can be trended. The 7.0 metre system length is the longer of the two standard 990 options and suits machines where the junction box is mounted away from the panel. Like all 990 series transmitters, the unit is loop powered from a 28 V supply, keeping the field installation to a single twisted pair, with no separate power cabling to pull through the conduit.
Engineering and Design
The transmitter conditions the probe signal and drives a 4 to 20 mAdc loop current proportional to the full-scale vibration value, so the control system reads live vibration without additional signal conditioning. The 04 full-scale option spans 0-4 mils pp (0-100 micrometres), and the 2-wire loop carries power and signal over the same pair, powered from a 28 V supply. A buffered gap voltage output is available for diagnostics during commissioning.
The 01 mounting option supplies 35 mm DIN rail clips, so the transmitter clips directly onto the rail in the control panel. The 7.0 metre system length matches the probe and extension cable installed on the machine, and the loop is wired in series with the controller input. During commissioning, the static gap voltage is checked and the loop current is compared with the vibration reading on a portable meter.
Routine checks on the 990 include reading the loop current with a portable meter and comparing the value with the machine vibration shown by the analyser. The gap voltage at the buffered output is recorded at commissioning and checked at each shutdown to detect probe tip drift. Loop power is confirmed at 28 V and the loop resistance is kept within specification so the output reaches full scale. When the transmitter is replaced, the new unit must carry the same full-scale option and system length as the removed unit; otherwise the reading is scaled differently and the machine must be re-verified. The recorded values are filed in the machine history so successive shutdown readings can be compared, and because the transmitter is loop powered no local supply wiring is needed in the junction box.
Key Features
- 2-wire 4 to 20 mA proportional vibration output
- 0-4 mils pp (0-100 micrometres) full-scale option
- 7.0 metre system length configuration
- 35 mm DIN rail clip mounting
- Buffered gap voltage output for diagnostics
- Loop powered from 28 V supply
- OEM-friendly compact transmitter
Applications
The 990 series is applied to centrifugal air compressors, small pumps, motors, fans and blowers on packaged and skid-mounted equipment. It is used where the control system needs a live vibration value, and as an upgrade from vibration switches on balance-of-plant machinery.
Specifications
| Part number | 990-04-70-01-00 |
| Series | 990 2-wire vibration transmitter |
| Full-scale | 04 (0-4 mils pp, 0-100 micrometres) |
| System length | 70 (7.0 m) |
| Mounting | 01 (35 mm DIN rail clips) |
| Approvals | 00 (not required) |
| Output | 4 to 20 mAdc proportional |
| Loop supply | 28 V |
Why Seven Star LLC
Seven Star LLC supplies verified Bently Nevada 990 series transmitters to OEM and maintenance programmes across Oman and the GCC. Every 990 is checked against the complete part number and full-scale option before your order is confirmed, and our team confirms the system length and loop supply for your installation.
Technical Specifications
The Bently Nevada 990-04-70-01-00 is a loop-powered, 2-wire radial vibration transmitter from the 990 family, bundling a 3300 NSv proximity probe, extension cable, and DIN-rail-mounted transmitter into a single OEM-oriented package. Per Baker Hughes’ 990-series naming convention, this configuration provides a 0–4 mils peak-to-peak full-scale displacement range over a 7.0m system length, with DIN-rail clip mounting and no hazardous-area agency approval on this specific order.
The transmitter outputs a 4–20mA signal proportional to peak-to-peak displacement at ±1.5% accuracy, powered from a +12 to +35V DC loop supply with a maximum loop resistance of 1,000Ω. The probe itself has a frequency response of 5Hz–6kHz (+0/-3dB) and a scale factor of 7.87mV/µm (200mV/mil) ±6.5%. Construction uses a PPS probe tip, AISI 303/304 stainless steel probe case, and a 75Ω FEP-insulated coaxial cable, with the transmitter itself potted to tolerate up to 100% condensing humidity. Rated operating temperature is -35°C to +85°C for the transmitter and -52°C to +177°C for the probe.
Certifications and Applications
The 990 family carries cNRTLus Class I Division 1&2 Groups A–D T4 certification, ATEX/IECEx Zone 0/2 (Ex ia/ec IIC T4) approval, RoHS compliance, and an optional ABS marine approval. Baker Hughes specifically positions this transmitter family for OEMs of centrifugal air compressors, small pumps, motors, and fans that need basic radial vibration protection and trending without the cost or complexity of a full multi-channel monitoring rack.
Why Seven Star LLC
Seven Star LLC supplies genuine Bently Nevada (Baker Hughes) 990-series vibration transmitters to OEMs and end users across Oman and the wider GCC, and confirms the exact full-scale range, system length, and mounting style required to match the customer’s machine and installation before confirming an order.
Request a Quote for Bently Nevada 990-04-70-01-00 2-Wire Vibration Transmitter
Submit a formal inquiry through our RFQ page with the transmitter part number 990-04-70-01-00, your vibration full-scale requirement and system length. 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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