3500/45 Position Monitor
Datasheet

Bently Nevada Machinery Condition Monitoring141537 Rev. M

Description
The 3500/45 Position Monitor is a 4-channel instrument that
accepts input from proximity transducers, Rotary Position
Transducers (RPTs), DC Linear Variable Differential
Transformers (DC LVDTs), AC Linear Variable Differential
Transformers (AC LVDTs), and rotary potentiometers. The
monitor conditions the input and compares the conditioned
signals with user-programmable alarms.
The type of measurement and transducer input
determine which I/O modules are required. See
Transducer Types for Position Measurements on
page 11., See Figures and Graphs on page 14., and
See I/O Modules for AC LVDTs and Rotary
Potentimeters on page 16.
You can program each channel using the 3500 Rack
Configuration Software to perform the following functions:l

Axial (thrust) PositionlDifferential ExpansionlStandard Single Ramp Differential ExpansionlNon-standard Single Ramp Differential Expansionl

Dual Ramp Differential ExpansionlComplementary Differential ExpansionlCase ExpansionlValve Position

3500/45 Position Monitor
Datasheet141537 Rev. M

The monitor channels areprogrammed in pairs and canperform up to two of these functions
at a time. For example, Channels 1
and 2 can perform one function whilechannels 3 and 4 may perform thesame or a different function.
The primary purpose of the 3500/45 Position
Monitor is to provide the following:llMachinery protection by continuously
comparing monitored parametersagainst configured alarm setpoints todrive alarms
Essential machine information for
operations and maintenance personnel

Each channel, depending on configuration,
typically conditions its input signal to generatevarious parameters called measured
variables. You can establish alert setpoints foreach active measured variable and danger
setpoints for any two of the active measured
variables.

2/21

3500/45 Position Monitor
Datasheet141537 Rev. M

Specifications
InputsSignalAC LVDT Case
Expansion

28.74 mV/V/mm(0.73 mV/V/mil),
15.35 mV/V/mm(0.39 mV/V/mil), or
9.45 mV/V/mm(0.24 mV/V/mil)

AC LVDT Valve
Position

28.74 mV/V/mm(0.73 mV/V/mil)
15.35 mV/V/mm(0.39 mV/V/mil),
9.45 mV/V/mm(0.24 mV/V/mil),
10.24 mV/V/mm(0.26 mV/V/mil),
7.48 mV/V/mm(0.19 mV/V/mil),
5.51 mV/V/mm(0.14 mV/V/mil),
3.94 mV/V/mm(0.10 mV/V/mil), or
3.15 mV/V/mm(0.08 mV/V/mil)RotaryPotentiometer
Valve Position

41 mV/degree rotation

Rotary Position
Transducer (RPT)
Valve Position

140 mV/deg rotation,
70 mV/deg rotation, or
50 mV/deg rotation

Accepts from 1 to 4 signal
inputs
7.7 watts, typical, using
Position I/O,
or

Power
consumption

DC LVDT Case
Expansion

0.05 V/mm (1.25 V/in),
0.08 V/mm (1.90 V/in),
0.10 V/mm (2.50 V/in),
0.18 V/mm (4.50 V/in),
0.20 V/mm (5.00 V/in), or
0.22 V/mm (5.70 V/in)

8.5 watts typical, using AC
LVDT I/O
or
5.6 watts typical, using
Rotary Potentiometer I/O

Input
Impedance

1 MΩ (DC LVDT inputs)
10 kΩ (Proximitor or RPT
inputs)137 kΩ (AC LVDT inputs)
200 kΩ (Rotary
Potentiometer inputs)

Sensitivity
ThrustDifferential
Expansion

Ramp Differential
Expansion

Complementary
Input Differential
Expansion

3.94 mV/μm (100 mV/mil)or7.87 mV/μm (200 mV/mil)
0.394 mV/μm (10 mV/mil)or
0.787 mV/μm (20 mV/mil)
0.394 V/mm (10 mV/mil),
0.787 V/mm (20 mV/mil),
3.937 V/mm (100 mV/mil),or
7.874 V/mm (200 mV/mil)

Outputs
Front Panel LEDs

0.394 V/mm (10 mV/mil),
0.787 V/mm (20 mV/mil),or
3.937 V/mm (100 mV/mil)

3/21

OK LED

Indicates when the 3500/45
Position Monitor is operating
properly.

TX/RX
LED

Indicates when the 3500/45
Position Monitor is communicatingwith other modules in the 3500
rack.

3500/45 Position Monitor
Datasheet

BypassLED

141537 Rev. M

Signal Conditioning

Indicates when the 3500/45
Position Monitor is in Bypass Mode.

Specified at +25 ºC (+77 ºF) unlessotherwise noted.

Transducer Power Supply
Proximitor or
RPT-24 Vdc

DC LVDT+15 Vdc

AC LVDT

2.3Vrms 3400Hz sine wave

RotaryPotentiometer-12.38 Vdc

Thrust and Differential Expansion
AccuracyFrequency Response+4 to +20 mA
Values are proportional tomonitor full-scale.
RecorderThe monitor provides
individual recorder values
for each channel except
Ramp and CIDE.

Resolution

Direct filter-3 dB at 1.2 Hz

Gap filter-3 dB at 0.41 Hz

Ramp Differential Expansion
Accuracy

Monitor operation isunaffected by short circuits
on recorder outputs.
VoltageCompliance(current
output)Within ±0.33% of full-scale
typical±1% maximum

See Ramp Differential
Expansion Accuracy on
page 13.

Frequency Response

0 to +12 Vdc range acrossload
Load resistance is 0 to 600Ω.

Direct filter-3 dB at 1.2 Hz

Gap filter-3 dB at 0.41 Hz

Complimentary Input Differential
Expansion (CIDE)

0.3662 µA per bit±0.25% error at room
temperature±0.7% error overtemperature range

Accuracy

Update rate 100 ms or lessWithin ±0.33% of full-scale
typical±1% maximum

Frequency Response
Direct filter-3 dB at 1.2 Hz

Gap filter-3 dB at 0.41 Hz

Case Expansion
Accuracy

4/21

Within ±0.33% of full-scale
typical±1% maximum

3500/45 Position Monitor
Datasheet141537 Rev. M

AlarmsFrequency Response
Direct filter-3 dB at 1.2 Hz

Gap filter-3 dB at 0.41 Hz

Use the 3500 Rack
Configuration Software to
set alert and danger levels
for the direct values
measured by the monitor.

Valve Position
Accuracy

Alarm
Setpoints

Within ±0.33% of full-scale
typical±1% maximum

Frequency Response
Direct filter-3 dB at 1.2 Hz

Gap filter-3 dB at 0.41 Hz

Accuracy ofalarm
setpoints

PhysicalMonitor Module (Main Board)
Dimensions(Height x Width x
Depth)

241.3 mm x 24.4 mm x241.8 mm
(9.50 in x 0.96 in x 9.52 in)Weight0.91 kg (2.0 lb)

241.3 mm x 24.4 mm x 99.1
mm
(9.50 in x 0.96 in x 3.90 in)

Weight0.20 kg (0.44 lb)

You can program alarm delays using
the 3500 Rack Configuration Softwarefrom one to 60 seconds in one
second intervals.

Alert

From one to 60 seconds in
one second intervals

Danger

0.1 seconds or from one to 60
seconds in 0.1 second
intervals

Rack Space Requirements
Monitor
Module1 full-height front slot

I/O Modules

1 full-height rear slot

Within 0.13% of the desired
value

Alarm Time Delays

I/O Modules
Dimensions(Height x Width x
Depth)

Alarms are adjustable from0 to 100% of full-scale foreach measured value.
However, when the full-scale
range exceeds the range ofthe transducer, the range ofthe transducer will limit the
setpoint.

Measured Variables
Position measurements are used formachine protection and condition
monitoring. The 3500/45 Position
Monitor returns values for thefollowing measured variables
depending on configuration.

Thrust Position

5/21

DirectGap

3500/45 Position Monitor
Datasheet141537 Rev. M

Differential
expansion

DirectGap

Firmware and Software
Requirements

Ramp
Differential
ExpansionComposite
DirectGap

When adding the 3500/45 Position Monitor to
an existing 3500 system, the following firmware
and software versions or later are required:

CIDE

Composite
DirectGap

CaseexpansionComposite
Direct and position

Value position

Direct and positionl

3500/20 RIM Firmware rev. Gl3500 Configuration Software 2.41l

3500 Data Acquisition 2.20l

3500 Operator Display 1.20lEnvironmental LimitslOperatingTemperature

When used with
Internal/External Termination
I/O Module:-30°C to +65°C(-22°F to +150°F)

Storage
Temperature-40°C to +85°C(-40°F to +185°F)

Humidity95%
Non-condensing

l

6/21

3500/93 Display Interface Module
135799-01
Firmware rev. G
For Valve Position using RPT, you musthave 3500 Configuration Software 3.00 or
greater.

3500/45 Position Monitor
Datasheet141537 Rev. M

Hazardous Area Approvals

Compliance and Certifications

For the detailed listing of country andproduct-specific approvals, refer tothe Approvals Quick Reference Guide(108M1756).

FCC
This device complies with part 15 of the
FCC Rules. Operation is subject to thefollowing two conditions:ll

For additional technicaldocumentation, please log in to
bntechsupport.com and access the
Bently Nevada Media Library.

This device may not cause harmfulinterference.
This device must accept any
interference received, includinginterference that may cause
undesired operation.

cNRTLusClass I, Zone 2: AEx/Ex nA nC ic IIC T4 Gc;
Class I, Zone 2: AEx/Ex ec nC ic IIC T4 Gc;
Class I, Division 2, Groups A, B, C, and D;

EMC
European Community Directive:

T4 @ Ta= -20˚C to +65˚C (-4˚F to +149˚F)
When installed per drawing 149243 or
149244.

EMC Directive 2014/30/EU
Standards:

ATEX/IECEx

EN 61000-6-2; Immunity for
Industrial Environments
EN 61000-6-4; Emissions for
Industrial Environments

II 3 GEx nA nC ic IIC T4 Gc
Ex ec nC ic IIC T4 Gc

Electrical Safety

T4 @ Ta= -20˚C to +65˚C(-4˚F to +149˚F)
When installed per drawing 149243 or
149244.

European Community Directive:
LV Directive 2014/35/EU
Standards:
EN 61010-1

RoHS
European Community Directive:
RoHS Directive 2011/65/EU

Maritime
DNV GL rules for classification – Ships,
offshore units, and high speed and lightcraft
ABS Rules for Condition of Classification,
Part 1ll

Steel Vessels Rules
Offshore Units and Structures

7/21

3500/45 Position Monitor
Datasheet141537 Rev. M

When using the 3500/45 Position Monitor in a
TMR application, valve position measurement
are not available, and case expansion
measurements are only supported for Discrete
TMR.

Ordering
Information

External Termination Blocks

For the detailed listing of country andproduct-specific approvals, refer tothe Approvals Quick Reference Guide(108M1756).
For additional technicaldocumentation, please log in to
bntechsupport.com and access the
Bently Nevada Media Library.

Position Monitor
3500/45 - AA-BB

132242-01

Prox/Seismic TMR I/O Bussed
External Termination Block(Euro-style connectors) for
Proximitor inputs

132234-01

TMR I/O Busses External
Termination Block
Terminal Strip connectors

125808-06

Position External Termination
Block (Euro-style connectors) for
Proximitor, RPT and DC LVDT
inputs128015-06

Position External Termination
Block (Terminal Strip
connectors) for Proximitor, RPT
and DC LVDT inputs

141208-01

AC LVDT External Termination
Block (Euro-style connectors) for
AC LVDT inputs

A: I/O Module Type
01

02

Position I/O Module with Internal
Terminations (Proximitor, RPT, DC LVDT)
Position I/O Module with External
Terminations (Proximitor, RPT, DC LVDT)

03

Discrete TMR Position I/O Module with
External Terminations (Proximitor or DC
LVDT)

141216-01

AC LVDT External Termination
Block (Terminal Strip
connectors) for AC LVDT inputs

04

Bussed TMR Position I/O Module with
External Terminations (Proximitor)

128702-01

Recorder External Termination
Block (Euro-style connectors)

05

AC LVDT Position I/O Module with
Internal Terminations

128710-01

06

AC LVDT Position I/O Module with
External Terminations

Recorder External Termination
Block (Terminal Strip
connectors)

B: Agency Approval
00

None

01

cNRTLus (Class 1, Division 2)

02

ATEX / IECEx / CSA (Class 1, Zone 2)

You must order external termination blocks andcables separately for each I/O module withexternal termination.

8/21

3500/45 Position Monitor
Datasheet141537 Rev. M

CablesSpares3500 Transducer (XDCR) to External
Termination (ET) Block Cable
129525 - AAAA-BB

176449-04

3500/45 Position
Monitor

A: I/O Cable Length

135137-01

Position I/O Modulewith Internal
Terminations for use
with Proximitors, RPTs
or DC LVDTs

135145-01

Position I/O Modulewith External
Terminations for use
with Proximitors, RPTs
or DC LVDTs

139554-01

AC LVDT Position I/O
Module with Internal
Terminations for use
with AC LVDTs

139567-01

AC LVDT Position I/O
Module with External
Terminations for use
with AC LVDTs

125808-06

Position-Prox/DC LVDT
- Euro141208-01

Position-Prox/AC LVDT
- Euro132242-01

Prox/Seis TMR ET Block- Euro128702-01

Recorder ET Block Euro

128015-06

Position External
Termination Block(Terminal Strip
connectors) for
Proximitor, RPT and DC
LVDT inputs

141216-01

AC LVDT External
Termination Block(Terminal Strip
connectors) for AC
LVDT inputs

0005

5 feet (1.5 metres)

0007

7 feet (2.1 metres)0010

10 feet (3.0 metres)

0025

25 feet (7.6 metres)0050

50 feet (15.2 metres)

0100

100 feet (30.5 metres)

B: Assembly Instructions
01

Not assembled

02

Assembled

3500 Recorder Output to External
Termination (ET) Block Cable
129529 - AAAA-BB
A: I/O Cable Length0005

5 feet (1.5 metres)

0007

7 feet (2.1 metres)0010

10 feet (3.0 metres)

0025

25 feet (7.6 metres)0050

50 feet (15.2 metres)

0100

100 feet (30.5 metres)

B: Assembly Instructions
01

Not assembled

02

Assembled

9/21

3500/45 Position Monitor
Datasheet141537 Rev. M

132234-01

TMR I/O Busses
External Termination
Block
Terminal Strip
connectors

128710-01

Recorder External
Termination Block(Terminal Strip
connectors)

166M4363

Connector Header
Push-in-Spring Type
(Alternative for PN
00580441)

166M2389

Connector Header
Push-in-Spring Type
(Alternative for PN
00580434)

166M2388

Connector Header
Push-in-Spring Type
(Alternative for PN
00580432)

166M2379

Connector Header
Push-in-Spring Type
(Alternative for PN
00580443)

10/21

3500/45 Position Monitor
Datasheet141537 Rev. M

Transducer Types for Position Measurements
The following table lists transducer types for each position measurement:
Measurement

Transducer Type
Proximitors

Thrust

3300XL 8 mm
3300 8 mm
3300 5 mm
3300 16 mm HTPS
7200 5 mm
7200 8 mm

7200 11 mm
3300XL 11mm
7200 14 mm
3000 (-18V)
3000 (-24V)
3300 RAM
Proximitors

Differential Expansion

25 mm Extended Range
35 mm Extended Range
50 mm Extended Range
Proximitors For Ramp andFlat Channels

Ramp Differential Expansion

3300XL 11mm
7200 11 mm
7200 14 mm
3300 16 mm HTPS
25 mm Extended Range
35 mm Extended Range
50 mm Extended Range
50 mm DE Transducer

Proximitors For Flat Channel

3300XL 8 mm
3300 8 mm
7200 5 mm
7200 8 mm

Proximitors
Complementary Input
Differential Expansion

3300XL 11mm
7200 11 mm
7200 14 mm
3300 16 mm HTPS
25 mm Extended Range

35 mm Extended Range
50 mm Extended Range
50 mm DE Transducer

DC LVDTs
Case Expansion (Channels 3
and 4 only)

25 mm (1 in)
50 mm (2 in)
101 mm (4 in)

AC LVDTs
25 mm (1 in)
50 mm (2 in)
101 mm (4 in)

11/21

3500/45 Position Monitor
Datasheet141537 Rev. M

Measurement

Transducer TypeAC LVDTs

Valve Position

25 mm (1 in)
50 mm (2 in)
101 mm (4 in)
152 mm (6 in)
03 mm (8 in)
254 mm (10 in)
304 mm (12 in)
508 mm (20 in)

Rotary Potentiometer

Rotary Position
Transducer

100° FS
50° FS rotation to 300°
200° FS
FS rotation
300° FS

12/21

3500/45 Position Monitor
Datasheet141537 Rev. M

Ramp Differential Expansion Accuracy
Channel Pair Type and Configuration Parameters
Maximum Tolerance inPercent of Full-Scale

Standard Single Ramp
Differential Expansion

Nonstandard Signal
Ramp Differential
Expansion

Dual Ramp
Differential
Expansion±1.0

Ramp angles 4 - 45 degrees
Greater than 3 Vdc fullscale spanSame model transducers oneach channel±1.25

Ramp angles 4 - 70 degrees
Greater than 3 Vdc fullscale span
N/A
Same model transducer onboth channels

N/A

±1.5

Ramp angles 4 - 70 degrees
Greater than 3 Vdc fullscale span
N/A
Different model transduceron each channel

N/A

±2.0

Ramp angles 4 - 70 degrees
Less than 3 Vdc full-scale
span
Same or Different modeltransducer on each channel

13/21

Ramp angles 4 - 70
degrees
Greater than 3 Vdc fullscale span

Ramp angles 4 - 70
degreeLess than 3 Vdc full-scale
span

Ramp angles 4 70 degrees
Greater than 3
Vdc full-scale
span

Ramp angles 4 70 degrees
Less than 3 Vdc
full-scale span

3500/45 Position Monitor
Datasheet141537 Rev. M

Figures and Graphs

1.
2.
3.
4.
5.
6.
7.
8.

Front View of 3500/45 Position Monitor
Status LEDs
Buffered Transducer Outputs
Rear Views of I/O Modules with Proximitors, Rotary Position
Tranducers or DC LVDTs.
Position I/O Module, Internal Termination, for Use with
Proximitors, Rotary Position Transducers, or DC LVDTs
Position I/O Module, External Termination, for Use with
Proximitors, Rotary Position Transducers, or DC LVDTs
Position I/O Module, TMR Discrete, External Termination, for
Use with Proximitors or DC LVDTs
Prox/Seismic I/O Module, TMR Bussed, External Termination
for Use with Proximitors

Figure 1: Front and Rear Views of 3500/45 Position Monitor and I/O modules for use with
Proximitor, Rotary Position Transducer and DC LVDT I/Os

14/21

3500/45 Position Monitor
Datasheet141537 Rev. M

Figure 2: Side View of I/O Modules
The I/O modules with internal or external terminations have the same jumpers.

15/21

3500/45 Position Monitor
Datasheet141537 Rev. M

1. Rear Views of I/O Modules Used with AC LVDTs
2. Position I/O Module, Internal Termination, for Use with AC
LVDTs
3. Position I/O Module, External Termination, for Use with AC
LVDTs
4. Rear Views of I/O Modules Used with Rotary
Potentiometers
5. Position I/O Module, Internal Termination, for Use with
Rotary Potentiometers
6. Position I/O Module, External Termination, for Use with
Rotary Potentiometers
Figure 3: I/O Modules for AC LVDTs and Rotary Potentimeters

16/21

3500/45 Position Monitor
Datasheet141537 Rev. M

Thrust and Valve Positions
Thrust Position
The following picture depicts the axial position of the rotor with respect to the thrust bearing or somefixed reference:

Valve Position
The following picture depicts the relative measurement of the position of a process inlet valve stem
based on its full stroke, or the relative measurement of the rotational position of a cam shaft based on
its full rotation:

17/21

3500/45 Position Monitor
Datasheet141537 Rev. M

Differential Expansion
The following picture depicts shaft growth relative to the machine case:

The following picture depicts standard single ramp differential expansion:

18/21

3500/45 Position Monitor
Datasheet141537 Rev. M

The following picture depicts non-standard single ramp differential expansion:

The following picture depicts a dual ramp differential expansion:

The following image depicts a complementary input differential expansion (CIDE) which uses a
combination of two probes to increase the measurement range to twice the range of a single proble:

19/21

3500/45 Position Monitor
Datasheet141537 Rev. M

Case Expansion
The following picture depicts a single case expansion which is the measurement of the machine casing
growth relative to its foundation:

The following picture depicts a dual case expansion:

20/21

3500/45 Position Monitor
Datasheet141537 Rev. M

Copyright 2023 Baker Hughes Company. All rights reserved.

Bently Nevada, M2, Proximitor and Orbit Logo are registered trademarks of Bently Nevada, a Baker Hughes business,in the United States and other countries. The Baker Hughes logo is a trademark of Baker Hughes Company. All otherproduct and company names are trademarks of their respective holders. Use of the trademarks does not imply any
affiliation with or endorsement by the respective holders.
Baker Hughes provides this information on an “as is” basis for general information purposes. Baker Hughes does notmake any representation as to the accuracy or completeness of the information and makes no warranties of any
kind, specific, implied or oral, to the fullest extent permissible by law, including those of merchantability and fitness
for a particular purpose or use. Baker Hughes hereby disclaims any and all liability for any direct, indirect,
consequential or special damages, claims for lost profits, or third party claims arising from the use of theinformation, whether a claim is asserted in contract, tort, or otherwise. Baker Hughes reserves the right to makechanges in specifications and features shown herein, or discontinue the product described at any time without
notice or obligation. Contact your Baker Hughes representative for the most current information.
The information contained in this document is the property of Baker Hughes and its affiliates; and is subject tochange without prior notice. It is being supplied as a service to our customers and may not be altered or its content
repackaged without the express written consent of Baker Hughes. This product or associated products may becovered by one or more patents. See Bently.com/legal.

1631 Bently Parkway South, Minden, Nevada USA 89423
Phone: 1.775.782.3611 (US) or Bently.com/support
Bently.com

21/21