NSK Bruel & Kjaer Vibro ds821 Series User manual

Keep accessible for future reference
Instructions
Displacement sensor system series
ds821
Measuring range 4 mm

Copyright © 2022 Brüel & Kjær Vibro GmbH
All rights to this technical documentation remain reserved.
Any corporeal or incorporeal reproduction or dissemination of this technical documentation or making this
document available to the public without prior written approval from Brüel & Kjær Vibro GmbH shall be
prohibited. This also applies to parts of this technical documentation.
Instructions Sensor ds821 4 mm, C104958.002 / V04, en, date of issue: 07.03.2022
Brüel & Kjær Vibro GmbH
Leydheckerstrasse. 10
64293 Darmstadt
Germany
Phone: [phone]
Fax: [phone]
Brüel & Kjær Vibro A/S
Lyngby Hovedgade 94, 5 sal
2800 Lyngby
Denmark
Phone: [phone]
Fax: [phone]
BK Vibro America Inc
1100 Mark Circle
Gardnerville NV 89410
USA
Phone: [phone]
Hotline
Phone: [phone]
E-Mail: [email protected]
Homepage
www.bkvibro.com
Corporate E-Mail
[email protected]

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Brüel & Kjær Vibro │Instructions Sensor ds821 4 mm
Table of Contents
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UNRESTRICTED DOCUMENT
Table of Contents
1Safety........................................................................................................................5
1.1 Disclaimer..............................................................................................................................................5
1.2 Intended usage......................................................................................................................................5
1.3 Limitations.............................................................................................................................................6
1.4 General information..............................................................................................................................6
1.5 User Qualification .................................................................................................................................6
1.5.1 Recommendations to User.....................................................................................................................................6
1.5.2 Prohibition of Unauthorized Modifications ..............................................................................................................7
1.6 Information on delivery and transport................................................................................................7
1.7 Information on assembly and disassembly.......................................................................................7
2Product description.................................................................................................9
2.1 Basic function.......................................................................................................................................9
2.2 Components of the displacement sensor system.............................................................................9
2.3 Nominal overall length of the displacement sensor system..........................................................10
3Delivery, storage, transport..................................................................................11
3.1 Delivery................................................................................................................................................11
3.2 Storage and transport ........................................................................................................................11
4Installation..............................................................................................................12
4.1 Assembling the displacement sensor..............................................................................................13
4.1.1 Displacement sensor for front-side mounting.......................................................................................................13
4.1.2 Displacement sensor for rear-side mounting........................................................................................................14
4.2 Assembling the driver (oscillator/demodulator)..............................................................................14
4.2.1 Mounting on hat-rail..............................................................................................................................................14
4.2.2 Screw mounting....................................................................................................................................................15
4.3 Connect the components together ...................................................................................................16
4.3.1 Connecting and disconnecting plug connections..................................................................................................16
4.3.2 Connection via extension cable............................................................................................................................16
4.3.3 Direct connection..................................................................................................................................................16
4.4 Setting up the measuring chain and the displacement sensor .....................................................17
4.4.1 Measurement set-up ............................................................................................................................................17
4.5 Electrical connection..........................................................................................................................18

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5Functional check ...................................................................................................19
5.1 Quick check.........................................................................................................................................19
5.2 Troubleshooting..................................................................................................................................19
6Disassembly...........................................................................................................21
6.1 Disconnecting the connecting plugs................................................................................................21
6.2 Driver disassembly.............................................................................................................................21
6.2.1 Disassembling driver with assembly adapter on hat-rail.......................................................................................21
6.2.2 Disassembling driver with assembly adapter, screw-mounted.............................................................................21
6.3 Replacing displacement sensor system components....................................................................21
7Disposal..................................................................................................................22
8Technical data........................................................................................................23
8.1 Non-contacting displacement sensor system Series ds821..........................................................23
8.2 Dimensioning of assembly adapter..................................................................................................24
8.3 Environmental requirements.............................................................................................................25
8.3.1 Reliability of the displacement sensor in different media......................................................................................25
8.3.2 Properties of the measuring track.........................................................................................................................25
8.3.3 Required clearances and minimum distances for displacement sensors .............................................................26
8.4 Transfer characteristics.....................................................................................................................27
8.4.1 Characteristic curve for distance measurement [GAP / V]....................................................................................27
8.4.2 Characteristic curve for vibration measurement [ISF / mV/μm] ............................................................................27
8.4.3 Deviation from best fit straight line [DSL / μm]......................................................................................................27
9Measurement report..............................................................................................28
10 Declaration of conformity .....................................................................................29
11 Simplified diagram................................................................................................. 30

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Brüel & Kjær Vibro │Instructions Sensor ds821 4 mm
Safety
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UNRESTRICTED DOCUMENT
1 Safety
NOTE!
This manual is a part of the product. Read the manual carefully before using the product
and keep it accessible for future use.
CAUTION!
This symbol warns of dangerous situations which can result from misuse of the product.
NOTE!
This symbol provides general and useful information for using the product.
1.1 Disclaimer
Observing this technical documentation is a basic requirement for the proper and safe operation of
the product. We accept no liability for personal injury, damage to property or financial loss caused by
failure to observe this technical documentation. In such cases, any liability for material defects is
excluded.
1.2 Intended usage
The eddy-current displacement sensor system is intended solely for measuring mechanical distances
and oscillations and is used primarily for the condition monitoring of slide bearings or rotating shafts.
The use of the measuring chain is indoors or outdoors, when the driver is installed in a suitable
protective housing.
If sensors and cables are used in a way not described in the relevant user manuals, function and
protection may be impaired and serious personal damage, death or serious, irreversible injuries may
result.
•Exclusively use sensor as specified in data sheet. Any use other than specified is considered
inappropriate. Brüel & Kjær Vibro does not assume any liability for damages resulting from
inappropriate use. The user is solely responsible.
•Mounted sensors must not be used as steps.
•Ensure that system is exposed only to admissible environmental influences specified in
technical system data sheet.
•Maintain electrical equipment in regular intervals. Remedy defects, e.g. loose wires, defective
connectors, immediately.

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Hot surfaces
•In line with the user manuals, sensors and cables can be operated in extensive ambient
temperature ranges, whereby they can become hot through self-heating on housing walls and
can produce burning.
•When mounted at external heat or cold sources (e.g. machine parts), systems, sensors and
cables can adopt dangerous temperatures, whereby burning, among other things, can occur in
the event of contact.
1.3 Limitations
The eddy-current displacement sensor system may be used only within the scope defined by the
technical specifications.
Limitations of the user manual
Not all assembly and connection options are described in this manual.
1.4 General information
Never put damaged products into operation. Immediately report any damage.
1.5 User Qualification
Ensure that all work in conjunction with our systems is performed by skilled, expert and authorized
workers (for ATEX systems according to EN 60079-14). Among these works are:
Installation and Commissioning
Installation and commissioning primarily concern work on electrical equipment. These works may be
performed exclusively by electricians or workers instructed and supervised by an electrician in
accordance with electrotechnical regulations/directives.
Change of System Specification
Any change of system specification has its effects on monitoring process with stationary systems and
on the measuring sequence with portable measuring systems.
1.5.1 Recommendations to User
If the use of the system in conjunction with machines or plant sections can produce risks outside of
Brüel & Kjær Vibro's responsibility, the user is expected to prepare and distribute safety technical
instructions or warnings and to ensure that the personnel concerned has received and understood it.
CAUTION!
If system is integrated into a machine or designed to be assembled, commissioning must
not take place until the machine the system is to be integrated in conforms to the EC
directives.

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Brüel & Kjær Vibro │Instructions Sensor ds821 4 mm
Safety
EN
UNRESTRICTED DOCUMENT
1.5.2 Prohibition of Unauthorized Modifications
System and accessories must not be changed neither in construction nor safety technology without
the express consent of Brüel & Kjær Vibro. Any unauthorized modification excludes Brüel & Kjær
Vibro's liability for resulting damages.
1.6 Information on delivery and transport
CAUTION!
Protect the displacement sensor system from shocks, dust and dirt during storage and
transport. Protect the sensor tip using the supplied protective rubber cap.
1.7 Information on assembly and disassembly
NOTE!
To ensure that the displacement sensor system is functioning properly, do not change
the physical length of any of the system cables.
You must also ensure that the components used, the displacement sensor and the
extension cable, add up to a nominal system length of 5 m, 10 m or 25 m.
CAUTION!
Danger of injury through moving machine parts. Shut down the plant before installing the
displacement sensor.
CAUTION!
Live components can cause the driver to become defective. Close the electrical
connection and apply voltage only once all parts of the displacement sensor system
have been connected correctly.
NOTE!
The driver housings may not contact each other or any other conductive parts.

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Assembly of the sensor:
CAUTION!
The ceramic sensor tip is sensitive to shock. Transport and store the displacement
sensor only with the included protective rubber cap. Always keep the protective rubber
cap for later use.
To avoid damage, make sure, especially during assembly and while operating the
machine, that the sensor tip does not come into contact with other objects.
Loose ceramic particles can lead to damage within the machine.
Check the tip of the sensor for damage before every assembly. Never install a defective
sensor.
Assembly, disassembly or replacement of components:
NOTE!
Never pull the cable to open the connection. Doing so may damage the cable and the
connector ends.

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Brüel & Kjær Vibro │Instructions Sensor ds821 4 mm
Product description
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UNRESTRICTED DOCUMENT
2 Product description
Observe the safety information in chapter "Safety"!
2.1 Basic function
The displacement sensor systems of the ds82x family are based on the non-contacting eddy current
measurement process. The distance is measured between the tip of the displacement sensor and an
electrically conductive surface and sent via a proportional voltage signal to a subsequent electronic
monitor. This records the status of the rotating shafts as a part of surveillance of the machine.
2.2 Components of the displacement sensor system
The eddy-current displacement sensor system consists of the components of displacement sensor
with an integrated cable, an optional separate extension cable and the driver (oscillator/demodulator).
The name of a component is a combination of the series name ds821 and the component designation
(mc = complete system, ds = displacement sensor, ec = extension cable or od = driver). Each series
is available in system lengths of 5 m, 10 m and 25 m.
Figure 2-1) Example non-contacting displacement sensor system Series ds821
1.
Driver ds821.od13x
2.
Extension cable ds821.ec30x
3.
Colour coding: red denotes a measuring range of 4 mm
4.
Assembly adapter
5.
Displacement sensor ds821.ds300x

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2.3 Nominal overall length of the displacement sensor system
The nominal system length (N) refers to the length of the components displacement sensor (P) and
extension cable (L). The optional extension cable is required whenever the length of the displacement
sensor is 0.5 m or 1.0 m and with the help of the additional extension cable must be extended to the
nominal system length of 5 m, 10 m or 25 m.
If the displacement sensor already has the nominal system length, no additional extension cable is
required. In this case, the displacement sensor system consists only of the components displacement
sensor and driver.
Example: correct installation for a nominal length N of 5 m:
P = 0,5 m L = 4,5 m P+L = 5,0 m = N
Example of incorrect installation for a nominal length N of 5 m:
P = 0,5 m L = 4,0 m P+L = 4,5 m ≠N
It should be N = 5.0 m. The nominal overall length has not been complied with.