Brand: Bently Nevada

Bently Nevada 990-05-XX-03-05 2-Wire Vibration Transmitter

Name: Bently Nevada 990-05-XX-03-05 Transmitter, 4-20 mA
Brand: Bently Nevada

Description

Overview

The Bently Nevada 990-05-XX-03-05 transmitter is a 990 Vibration Transmitter. It is a two-wire, loop-powered device that turns the signal from a 3300 NSv proximity probe into a 4 to 20 mA output proportional to peak-to-peak vibration. Bently Nevada designed the 990 mainly for OEMs of centrifugal air compressors and of small pumps, motors and fans, who want to send a simple proportional vibration signal to the machinery control system. Alarm and protection logic then runs in that control system.

Under the ordering code 990-AA-BB-CC-DD, this part number decodes as follows:

05: full scale of 0-5 mils pp (0-125 micrometres pp)
XX: system length, either 50 (5.0 m) or 70 (7.0 m), to be confirmed from the installed probe and cable
03: DIN clips and screws for mounting
05: CSA Division 2, ATEX Zone 0 and ATEX Zone 2 approvals, including ABS maritime approval

Key Features

Integrated Proximitor sensor, so no external signal conditioner is needed
2-wire, loop-powered 4 to 20 mA output over the selected full-scale range
PROX OUT terminals and coaxial connector give a dynamic vibration and gap voltage signal for diagnostics
Non-interacting zero and span adjustments, plus a test input pin for checking the loop
Not OK / signal defeat circuit drives the output below 3.6 mA on a probe fault or loose connection
Potted construction for high humidity, up to 100% condensing

Technical Specifications

Parameter	Value
Part number	990-05-XX-03-05
Full scale (option 05)	0-5 mils pp (0-125 micrometres pp)
System length (option XX)	50 = 5.0 m or 70 = 7.0 m
Mounting (option 03)	DIN clips and screws
Agency approvals (option 05)	CSA Division 2, ATEX Zone 0, ATEX Zone 2, ABS maritime
Input	One 3300 NSv proximity probe and extension cable
Power	+12 to +35 V DC at the transmitter terminals
Output	4 to 20 mA DC, 2-wire
Loop accuracy	Within +/-1.5% of full scale
Maximum loop resistance	1,000 ohm including cable at 35 V DC
Probe gap	0.5 to 1.75 mm (20 to 55 mils)
Frequency response	5 Hz to 6,000 Hz (+0, -3 dB)
Transmitter operating temperature	-35 to +85 deg C
Transmitter weight	0.43 kg
Current limiting	23 mA typical
Power-up inhibit	Output held below 3.6 mA for 2 to 3 s after power is applied
PROX OUT scale factor	7.87 mV/µm (200 mV/mil) ±6.5 % typical, ±10 % worst case
PROX OUT linear range	1.4 mm, starting about 0.25 mm from the target
PROX OUT output impedance	10 kΩ, calibrated for a 10 MΩ load; lead to test equipment 3 m maximum
Minimum target size	9.5 mm diameter
Storage temperature (transmitter)	-52 to +100 °C
Probe temperature	-52 to +177 °C
Hazardous-area marking	Ex ia IIC T4 Ga and Ex ec IIC T4 Gc, Ta -30 to +85 °C
Transmitter size	100.1 × 73.9 mm footprint, 53.3 mm high; total system weight 0.82 kg typical

Applications

Overall vibration monitoring on centrifugal air compressors
Small pumps, motors, fans and blowers on balance-of-plant duty
Packaged and skid-mounted OEM equipment that sends vibration to a PLC or DCS analog input
Utility and water plant machinery where a full protection rack is not justified

Bently Nevada 990 Ordering Code and Options

The transmitter is coded 990-AA-BB-CC-DD. AA is the full-scale range: 04 (0 to 4 mils pp, 0 to 100 µm), 05 (0 to 5 mils pp, 0 to 125 µm), 08 (0 to 8 mils pp, 0 to 200 µm) or 10 (0 to 10 mils pp, 0 to 250 µm). BB is the system length, 50 for 5.0 m or 70 for 7.0 m. CC is mounting: 01 for 35 mm DIN-rail clips, 02 for bulkhead screws, 03 for both. DD is approvals: 00 none, 01 CSA Division 2, 05 CSA Division 2 with ATEX Zone 0 and Zone 2 plus ABS maritime approval. So 990-05-XX-03-05 is the 0 to 5 mil version with both mounting kits and the full approval set, in either length.

The probe and extension cable are ordered separately and must add up to the system length. Compatible 3300 NSv probes are 330901/330902 (1/4-28 UNF), 330908/330909 (3/8-24 UNF), 330903/330904 (M8 × 1), 330905/330910 (M10 × 1) and reverse-mount 330906/330907. Extension cable 330930 comes in 4.0, 4.5, 6.0 and 6.5 m.

Bently Nevada 990 Installation and Wiring Notes

Loop wiring is recommended as shielded twisted pair, 1.0 mm² (18 AWG). The usable loop resistance depends on supply voltage: 43.5 × (supply voltage – 12) Ω, reaching 1,000 Ω at 35 V; above that limit the output cannot reach 20 mA. The PROX OUT signal is not isolated from the loop and its phase is inverted compared with standard Bently Nevada Proximitor outputs. It can go straight to battery-powered or isolated instruments, but grounded AC-powered analysers can cause a false alarm, so the 990/991 Test Adapter 122115-01 is recommended. The 4 to 20 mA signal carries overall peak-to-peak amplitude only; gap alarms, phase data and Trip Multiply are not available.

Why Seven Star LLC

Seven Star LLC supplies Bently Nevada 990 transmitters and 3300 NSv transducer components to OEM and maintenance programmes across Oman and the GCC. Before quoting, we check the full-scale, system length, mounting and approval options against the nameplate of the existing transmitter and the installed probe and cable.

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, including the system length digits (for example 990-05-50-03-05 or 990-05-70-03-05)
The quantity
The part numbers of the 3300 NSv probe and extension cable
Your loop supply voltage

We will confirm the correct 990 configuration and respond with a formal quotation.

Where the 990-05-XX-03-05 transmitter is used

Centrifugal air compressors
Small pumps
Motors and fans
OEM machine packages
Machinery control systems

Selection checklist for the 990-05-XX-03-05 transmitter

Full-scale range
System length
Mounting method
Proximity probe type
Extension cable
Loop supply
Control system input
Part number match

Installation, commissioning and maintenance notes for the 990-05-XX-03-05 transmitter

Fix the transmitter with the DIN clips and screws and connect the probe and the loop wiring. Confirm the system length from the installed probe and cable. Check the wiring and the signal at regular intervals.

Requesting a quotation for the 990-05-XX-03-05 transmitter

Please send the system length, the probe type and the machine type. Seven Star LLC serves industrial customers in Oman and the GCC and replies with a quotation based on the information provided.

990-05-XX-03-05 device type

It is a 990 vibration transmitter.

990-05-XX-03-05 maker

It is made by Bently Nevada.

990-05-XX-03-05 wiring

It is a two-wire, loop-powered device.

990-05-XX-03-05 probe

It turns the signal of a 3300 NSv proximity probe into a 4 to 20 mA output.

990-05-XX-03-05 amplitude

The output is proportional to peak-to-peak vibration.

990-05-XX-03-05 customers

It is designed mainly for OEMs of centrifugal air compressors and small pumps, motors and fans.

990-05-XX-03-05 control system

Alarm and protection logic then runs in the machinery control system.

990-05-XX-03-05 order code

The ordering code is 990-AA-BB-CC-DD.

990-05-XX-03-05 full scale

Option 05 sets a full scale of 0 to 5 mils peak-to-peak.

990-05-XX-03-05 system length

Option XX is a system length of either 50 for 5.0 m or 70 for 7.0 m.

990-05-XX-03-05 length check

The length is confirmed from the installed probe and cable.

990-05-XX-03-05 mounting

Option 03 gives DIN clips and screws for mounting.

990-05-XX-03-05 proximitor

An integrated Proximitor sensor means no external signal conditioner is needed.

990-05-XX-03-05 diagnostics

PROX OUT terminals and a coaxial connector give a dynamic vibration and gap voltage signal.

990-05-XX-03-05 adjustments

Zero and span adjustments do not interact.

990-05-XX-03-05 test input

A test input pin supports checking of the loop.

990-05-XX-03-05 not OK circuit

The Not OK signal defeat circuit drives the output low on a probe fault or a loose connection.

990-05-XX-03-05 construction

The construction is potted for humid places.

990-05-XX-03-05 support

Seven Star LLC gives local technical support with selection.

Loop records for the 990-05-XX-03-05 transmitter

Record the loop signal, the system length and the date of each check.

Choosing the right 990-05-XX-03-05 transmitter length

Choose between the 5.0 m and 7.0 m versions from the installed probe and cable.

Other Models in the Bently Nevada 990 Vibration Transmitters Range

Seven Star LLC supplies models from the Bently Nevada 990 Vibration Transmitters range in Oman and the GCC. Compare the related models below and request a quote for the one that matches your application.

Model	Category
Bently Nevada 990-05-XX-03-05 2-Wire Vibration Transmitter	Vibration Monitoring	You are viewing this model
Bently Nevada 990-04-70-01-00 2-Wire Vibration Transmitter	Vibration Monitoring	View details
Bently Nevada 990-05-50-01-00 2-Wire Vibration Transmitter	Vibration Monitoring	View details
Bently Nevada 990-05-70-02-00 2-Wire Vibration Transmitter	Vibration Monitoring	View details

Datasheets & Documents

Datasheet Bently Nevada 990-05-XX-03-05 2-Wire Vibration Transmitter Datasheet Download

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About brand

Bently Nevada is the American machinery protection and condition monitoring brand behind the 3500 rack, the 3300 XL proximity probe and the System 1 software. It was founded in 1961 in Minden, Nevada, and is today a Baker Hughes business.

Seven Star LLC is an independent supplier in Muscat. We list Bently Nevada monitors, I/O modules, probes, proximitors, velocity transducers and transmitters for rotating equipment in Oman and the GCC, and source them by full part number.

Bently Nevada company profile

Established	1961, Minden, Nevada, USA, by Donald E. Bently. The business started earlier as Bently Scientific in Berkeley, California (1956).
Known for	The first commercial eddy-current proximity transducers for measuring shaft vibration and position on high-speed turbomachinery
Ownership	Acquired by GE Energy in 2002; part of Baker Hughes since GE Oil & Gas combined with Baker Hughes in 2017
Rack generations	5000 series (from 1965), 3300 series (from 1988), 3500 series (from 1995), Orbit 60 (current platform)
Product families	Machinery protection racks, proximity probes and proximitors, Keyphasor sensors, velocity and acceleration transducers, 2-wire vibration transmitters, general-purpose monitors, portable analyzers, wireless sensors and System 1 condition monitoring software
Typical machines	Steam and gas turbines, centrifugal and reciprocating compressors, pumps, motors, generators, fans and gearboxes

Milestones

1956: Donald E. Bently starts Bently Scientific in Berkeley, California.
1961: The company moves to Minden, Nevada, as Bently Nevada.
1965: The 5000 series monitoring system is introduced.
1988: The 3300 series follows.
1995: The 3500 machinery protection system is launched.
2002 and 2017: GE Energy acquires Bently Nevada; it becomes part of Baker Hughes in 2017.

Bently Nevada product series

Series	Type	What it does
3500	Machinery protection rack	Continuous online protection with alarm and danger relays. Modules include the 3500/15 power supply, 3500/20 rack interface, 3500/25 Keyphasor, 3500/42M proximitor/seismic, 3500/50 tachometer, 3500/60 temperature, 3500/33 relay and 3500/92 communication gateway
3500 recip modules	Reciprocating compressor monitoring	3500/70M impulse velocity, 3500/72M rod position and 3500/77M cylinder pressure
Orbit 60	Protection and monitoring platform	The current Bently Nevada platform for protection, condition monitoring and data integration with System 1
3300 XL 8 mm	Proximity transducer system	Probe, extension cable and proximitor sensor for radial vibration, thrust position and Keyphasor reference on fluid-film bearing machines; also 5 mm and 25 mm versions
330500 Velomitor, 190501 Velomitor CT	Piezo-velocity sensors	Casing velocity on rolling-element bearing machines and low-speed cooling tower fans
990 and 991	2-wire transmitters	4-20 mA vibration (990) and thrust position (991) signals straight into a PLC or DCS, without a monitor rack
1900/65A, 2300	Compact monitors	Protection for balance-of-plant pumps, fans and motors where a full 3500 rack is not justified

A proximity probe measures the gap to the shaft, so it sees shaft movement inside a fluid-film bearing directly. A velocity or acceleration sensor sits on the casing and suits rolling-element bearing machines. Critical turbomachinery usually carries two X-Y probes per bearing, two axial probes for thrust position and a Keyphasor probe for speed and phase.

Where Bently Nevada systems are used

In Oman and the GCC, Bently Nevada racks and probes protect gas turbines, compressors and steam turbines in gas processing, LNG, refining, petrochemical, power and desalination plants. Many installations are 3500 racks that have run for years, so most requests are for like-for-like module, probe, extension cable and proximitor replacements, plus upgrades to newer monitors.

Ordering and replacement: what we need

For probes and proximitors, send the full part number with all option digits (for example 330101-00-27-10-02-05). The digits set the probe length, cable length, connector and approvals, and the probe, cable and proximitor must match in total system length. For 3500 modules, send the module and I/O part numbers from the rack and say whether the I/O is internal or external termination, or barrier type. If a module is obsolete, we quote the replacement that Bently Nevada names and point out any configuration or firmware change.

Facts checked against Baker Hughes Bently Nevada pages and published company history, October 2026.

Browse Bently Nevada products by category: Vibration.

FAQ

Questions about the Bently Nevada 990-05-XX-03-05 2-Wire Vibration

Answers from our engineering team on installation, compatibility and integration.

01What is the 990 vibration transmitter used for?

It is a two-wire transmitter that converts machine casing vibration into a 4 to 20 mA signal for the control system, with no separate power supply needed.

02What does the part number 990-05-XX-03-05 identify?

It identifies a 990 with 0-5 mils peak-to-peak full scale, DIN clips and screw mounting, and the complete approval option set; the XX position is the system length, which should be confirmed from the installed cable.

03How is the 990 installed?

The transmitter mounts on a 35 mm DIN rail or by bulkhead screws according to the part number option, and connects to the probe with its matched cable.

04What loop supply does the 990 need?

The transmitter is loop powered and is designed for a 28 V supply; the loop resistance must stay within the rating so the output reaches 20 mA at full scale.

05Which machines use the 990 series?

Centrifugal air compressors, small pumps, motors, fans and similar rotating machines where a live vibration signal is required without a full monitoring rack.