Brand: Bently Nevada

Bently Nevada 990-04-70-01-00 2-Wire Vibration Transmitter

Name: Bently Nevada 990-04-70-01-00 Vibration Transmitter
Brand: Bently Nevada

Description

Overview

The Bently Nevada 990-04-70-01-00 is a 990 Vibration Transmitter, a 2-wire, loop-powered device intended mainly for OEMs of centrifugal air compressors and small pumps, motors or fans that want a simple 4 to 20 mA vibration signal as the input to their machine control system. It accepts a 3300 NSv proximity probe and matching extension cable (ordered separately), conditions the signal into peak-to-peak vibration amplitude and outputs it as a proportional 4 to 20 mA signal.

In the 990-AA-BB-CC-DD order code, this unit is configured for a 0-4 mils pp (0-100 µm pp) full-scale range, a 7.0 m system length, 35 mm DIN-rail clip mounting and no agency approval. A transmitter provides overall vibration trending and alarming but not the diagnostic functions of a continuous monitoring system.

Key Features

Integrated Proximitor Sensor; no external signal conditioner required
Non-isolated PROX OUT terminals and coaxial connector for dynamic and gap signal diagnostics
Non-interacting zero and span adjustments and a Test Input pin
Not OK / signal defeat and power-up inhibit circuits
Potted construction for up to 100% condensing humidity

Technical Specifications

Parameter	Value
Part number	990-04-70-01-00
Full-scale option	04: 0-4 mils pp (0-100 µm pp)
System length option	70: 7.0 m
Mounting option	01: 35 mm DIN-rail clips
Agency approval option	00: not required
Input	One 3300 NSv proximity probe and extension cable
Power	+12 to +35 Vdc at transmitter terminals
Output	4 to 20 mA over full-scale range, 2-wire loop
Loop accuracy	±1.5% over full-scale range
Max. loop resistance	1,000 Ω including cable at 35 Vdc
Current limiting	23 mA typical
Not OK / signal defeat	Output <3.6 mA within 100 µs of Not OK
Probe gap	0.5 to 1.75 mm (20 to 55 mils) for full-scale range
Prox Out linear range	1.4 mm (55 mils), from approx. 0.25 mm
Prox Out scale factor	7.87 mV/µm (200 mV/mil) ±6.5% typical
Frequency response	5 Hz to 6,000 Hz, +0/-3 dB
Minimum target	9.5 mm diameter
Transmitter operating temperature	-35 °C to +85 °C
Transmitter weight	0.43 kg
Transmitter storage temperature	-52 to +100 °C
Power-up inhibit	Output held below 3.6 mA for 2 to 3 s after power is applied
Recovery after Not OK	Output restored 2 to 3 s after the fault clears
Prox Out output impedance	10 kΩ, calibrated for a 10 MΩ load
Scale factor temperature stability	Within ±10 % of 7.87 mV/µm from 0 to +70 °C
Maximum Prox Out (BNC) lead length	3 m
Maximum loop cable length	13 km with 1.0 mm² (18 AWG) shielded twisted pair
Maximum loop resistance versus supply	43.5 × (supply voltage – 12) Ω
Probe temperature range	-52 to +177 °C operating and storage
Total system weight	0.82 kg typical
Mounting holes	5.8 mm diameter, 4 places

Applications

Radial vibration trending and alarming on packaged centrifugal air compressors
Small pumps, motors, fans and blowers on skids where a PLC or DCS reads a 4 to 20 mA vibration value
Balance-of-plant rotating equipment in water, power and oil & gas facilities

Bently Nevada 990-04-70-01-00 Ordering Code and Options

In 990-AA-BB-CC-DD, AA is the full-scale range of the 4 to 20 mA output: 04, 05, 08 or 10 for 0-4, 0-5, 0-8 or 0-10 mils peak-to-peak (100, 125, 200 or 250 µm). BB is the system length the transmitter is matched to, 50 for 5.0 m or 70 for 7.0 m of probe plus extension cable. CC is the mounting: 01 for 35 mm DIN-rail clips, 02 for bulkhead screws, 03 for both. DD is the agency approval: 00 none, 01 CSA Division 2, and 05 CSA Division 2 with ATEX Zone 0 and Zone 2 plus ABS maritime approval.

This part number is therefore a 0-4 mil (the most sensitive of the four ranges), 7.0 m, DIN-rail unit. Because it ends in 00 it has no hazardous-area approval and should not be selected for classified locations.

Bently Nevada 990-04-70-01-00 Selection Notes

The manufacturer is explicit about what a loop-powered transmitter cannot do. The 4 to 20 mA signal carries only overall peak-to-peak amplitude, so phase cannot be derived from it, and monitor functions such as gap alarms, Timed OK channel defeat, Danger Bypass and Trip Multiply are not available. A PLC or DCS reading the loop can trend and alarm on overall vibration but will not capture waveform data when an alarm occurs. Where diagnostics are needed, the PROX OUT signal has to be used with portable test equipment.

Why Seven Star LLC

Seven Star LLC supplies Bently Nevada (Baker Hughes) 990 series vibration transmitters to power, oil & gas, petrochemical and water customers across Oman and the GCC. Before quoting, we check the complete part number and the full-scale range, system length and mounting option against the equipment already installed, so the replacement matches the existing system.

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, the quantity, the required full-scale range and system length, and the installed 3300 NSv probe part number. We will confirm the correct configuration and respond with a formal quotation. | Inquiry Form

How the Bently Nevada 990-04-70-01-00 works

A proximity probe senses the shaft or the machine part. The transmitter conditions the probe signal into peak-to-peak vibration amplitude. It sends the amplitude as a proportional 4 to 20 mA signal on two wires.

Where the Bently Nevada 990-04-70-01-00 is used

Centrifugal air compressors
Small pumps
Motors
Fans
OEM machine control systems

Selection checklist for the Bently Nevada 990-04-70-01-00

Full-scale range
System length
Mounting type
Probe and cable
Power supply
Loop resistance
Target diameter
Order code

Installation, commissioning and maintenance notes for the Bently Nevada 990-04-70-01-00

Clip the transmitter to a 35 mm DIN rail and connect the probe. Wire the loop and set the probe gap. Check the zero and span adjustments at regular intervals.

Requesting a quotation for the Bently Nevada 990-04-70-01-00

Please send the order code, the probe type and the quantity needed. Seven Star LLC serves industrial customers in Oman and the GCC and replies with a quotation based on the information provided.

990-04-70-01-00 transmitter type

It is a 2-wire loop-powered vibration transmitter.

990-04-70-01-00 maker

It is made by Bently Nevada.

990-04-70-01-00 family

It belongs to the 990 Vibration Transmitter family.

990-04-70-01-00 main users

It is aimed mainly at OEMs of centrifugal air compressors.

990-04-70-01-00 probe

It accepts one 3300 NSv proximity probe and extension cable.

990-04-70-01-00 cable order

The probe and the cable are ordered separately.

990-04-70-01-00 output

The output is 4 to 20 mA over the full-scale range.

990-04-70-01-00 full scale

The full-scale option is 0 to 4 mils peak to peak.

990-04-70-01-00 metric range

That equals 0 to 100 micrometers peak to peak.

990-04-70-01-00 system length

The system length is 7.0 m.

990-04-70-01-00 mounting

Mounting is by 35 mm DIN-rail clips.

990-04-70-01-00 power

Power is plus 12 to plus 35 Vdc at the transmitter terminals.

990-04-70-01-00 loop resistance

The maximum loop resistance is 1,000 ohm including cable at 35 Vdc.

990-04-70-01-00 current limit

Current limiting is 23 mA typical.

990-04-70-01-00 Not OK output

The output falls below 3.6 mA when the signal is Not OK.

990-04-70-01-00 power-up inhibit

The output is held below 3.6 mA for 2 to 3 s after power is applied.

990-04-70-01-00 probe gap

The probe gap is 0.5 to 1.75 mm for the full-scale range.

990-04-70-01-00 frequency response

The frequency response is 5 Hz to 6,000 Hz.

990-04-70-01-00 minimum target

The minimum target is 9.5 mm in diameter.

990-04-70-01-00 adjustments

Zero and span adjustments do not interact.

990-04-70-01-00 test input

A Test Input pin is provided.

990-04-70-01-00 diagnostics

PROX OUT terminals and a coaxial connector give dynamic and gap signals.

990-04-70-01-00 temperature

Operating temperature runs from minus 35 to plus 85 degrees C.

990-04-70-01-00 weight

The transmitter weighs 0.43 kg.

990-04-70-01-00 trending

A transmitter gives overall vibration trending and alarming.

Vibration records for the Bently Nevada 990-04-70-01-00

Record the loop current, the probe gap and the date of each check.

Choosing the right Bently Nevada 990-04-70-01-00 range

Choose the full-scale range and the system length from the machine and the probe.

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	View details
Bently Nevada 990-04-70-01-00 2-Wire Vibration Transmitter	Vibration Monitoring	You are viewing this model
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 990-04-70-01-00 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 990-04-70-01-00 2-Wire Vibration

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

01What does the 990-04-70-01-00 identify?

A 990 vibration transmitter with 0-4 mils peak-to-peak full scale, 7.0 m system length, DIN rail clip mounting and no agency approval option.

02What is the full-scale range of this transmitter?

0 to 4 mils peak-to-peak, equivalent to 0 to 100 micrometres peak-to-peak, output as a proportional 4 to 20 mA signal.

03Does the 990 need a local power supply?

No, it is loop powered from the 28 V supply and the signal is carried on the same two wires.

04How is the transmitter mounted?

On a 35 mm DIN rail with the clip option, or by the mounting option selected in the part number.

05Why is the system length important?

The transmitter, probe and cable are matched by system length; a replacement must carry the same length option or the reading is scaled differently.