Bently Nevada 991 thrust transmitter, 2-wire 4–20 mA axial position, with 3300 NSv proximity probe
Pricing depends on specification, quantity and delivery location. Send your requirement and we reply with a costed quotation within 24 hours.
Quick overview
- Type: Vibration monitoring
- Signal / Protocol: 4–20 mA
- Hazardous area: Hazardous-area rated / option
- Genuine productsSourced from the manufacturer or authorised channels
- Delivery across BangladeshDhaka, Chattogram and all industrial zones
- After-sales supportInstallation guidance and warranty handling
- Reply within 24 hoursCall +880 1713 552466 or email hello@argonmark.com
Specifications
| General | |
|---|---|
| Part no. | BD-1563 |
| Category | Oil & Gas Instruments |
| Group | Instrumentation & Control |
| Brand | Bently Nevada |
| Model | 991 |
| Technical | |
| Type | Vibration monitoring |
| Signal / Protocol | 4–20 mA |
| Hazardous area | Hazardous-area rated / option |
Datasheet
Technical features
| Integrated Proximitor sensor | no separate driver needed |
|---|---|
| Simple 4–20 mA thrust signal for OEM compressors, small pumps, motors and fans | |
| Non-interacting zero and span; test input for quick loop checks | |
| Power-up inhibit and Not OK / signal defeat prevent false alarms from a faulty probe or loose connection | |
| Potted for up to 100% condensing humidity; DIN-rail or bulkhead mounting | |
Applications
| Thrust (axial position) monitoring on centrifugal air compressors | |
| Small pumps, motors and fans with control-system alarming |
Key specifications
| Input | 3300 NSv proximity probe and extension cable (5 m or 7 m system) |
|---|---|
| Output | 4–20 mA 2-wire, loop powered (12–35 V DC) |
| Full-scale ranges | 0.6-0-0.6 mm or 25-0-25 mils |
| Accuracy | ±1.5% of full scale typical |
| Diagnostic output | PROX OUT (7.87 mV/µm) via terminals and coaxial connector |
| Approvals | ATEX/IECEx Ex ia IIC T4 Ga, Ex nA IIC T4 Gc; CSA Class I Div 2; ABS maritime |
Specification
| Input | 1 non-contacting 3300 NSv probe with extension cable |
|---|---|
| Power | +12 to +35 V DC at the transmitter |
| Output | 4–20 mA over full scale, 2-wire |
| Accuracy | Within ±1.5% of full scale (typical) |
| Max. loop resistance | 1,000 Ω at 35 V DC; 13 km max. to receiver |
| Current limiting | 23 mA typical |
| Not OK response | Output < 3.6 mA within 100 µs; restored within 0.1 s |
| Linear range | 0.25 to 1.65 mm (10 to 65 mils) |
| PROX OUT scale factor | 7.87 mV/µm (200 mV/mil) ±6.5%; 10 kΩ output impedance |
| Minimum target | 9.5 mm diameter (AISI 4140 steel) |
| Temperature | Transmitter −35 to +85 °C; probe −35 to +177 °C; storage −51 to +100 °C |
| Materials | Probe tip PPS; case 303/304 SS; FEP-insulated 75 Ω coax; optional SS armour |
| Weight | Transmitter 0.43 kg; system ≈ 0.82 kg |
| Approvals | ATEX/IECEx II 1 G Ex ia IIC T4 Ga; II 3 G Ex nA IIC T4 Gc; CSA Class I Div 2 Groups A–D; ABS type approval; CE |
Notes
| Data from the manufacturer's published datasheet. Confirm model, range, materials and approvals with Argonmark before ordering. |
Photo: courtesy of Bently Nevada, used with permission (source) — background removed by Argonmark. All photo credits
Description
The Bently Nevada 991 is a two-wire, loop-powered thrust transmitter that converts the signal from a 3300 NSv proximity probe into a 4–20 mA signal proportional to shaft axial position, for machinery control systems on compressors, small pumps, motors and fans. It has an integrated Proximitor sensor, so no separate driver is needed.
A diagnostic PROX OUT signal is available for vibration analysis, and zero/span adjustment, a test input and Not OK / signal defeat logic make it easy to commission and protect against false alarms. It is potted for wet environments and approved for Zone 0 (Ex ia) and Class I Div 2.
Argonmark Ltd supplies Bently Nevada instruments across Bangladesh — Dhaka, Chattogram, Gazipur, Narayanganj and the gas fields, refineries, terminals and power plants beyond. Send us the model, range, process connection, output and any hazardous-area requirement, and we will confirm the right configuration, lead time and price.
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