SKF CMSS 60 User manual

Eddy Probe Systems
Technical Manual
Part number: CMSS 31075800
Revision G
October 2008

Description Page
SKF Reliability Systems Limited Warranty......................................... v
Service information.........................................................................Back
Section 1 – General information
Introduction ........................................................................................1-1
Introduction to manual.....................................................................1-2
Initial inspection.................................................................................1-2
Unpacking ...........................................................................................1-2
Equipment furnished.........................................................................1-2
Inspection for physical damage.......................................................1-2
Reshipment procedure......................................................................1-3
Returned equipment with warranty or damage claims...............1-3
Selecting an eddy probe system .....................................................1-3
Range ..................................................................................................1-3
Sensitivity............................................................................................1-3
System length ....................................................................................1-3
Probe case ..........................................................................................1-3
Some eddy probe options ................................................................1-4
Armor ..................................................................................................1-4
Certification.........................................................................................1-4
A word about......................................................................................1-4
Probe tips............................................................................................1-4
Installation ..........................................................................................1-4
Target material...................................................................................1-4
Runout.................................................................................................1-4
Intrinsic safety....................................................................................1-4
API Standard 670..............................................................................1-4
Operating considerations..................................................................1-6
Target material...................................................................................1-6
Mounting area....................................................................................1-6
Environment.......................................................................................1-6
Hazardous areas................................................................................1-6
Preinstallation checklist.....................................................................1-7
Instrument selection .........................................................................1-7
Installation ..........................................................................................1-7
Description Page
Section 2 – Typical eddy probe arrangement
plans
Typical eddy probe arrangement plans ..........................................2-1
Radial shaft vibration probes ...........................................................2-3
Bearing cap mounting ......................................................................2-3
Bearing housing mounting ..............................................................2-4
Axial probe installation......................................................................2-5
Axial probe installation recommendations.....................................2-5
Section 3 – Probe installation
Introduction ........................................................................................3-1
Mounting the probe...........................................................................3-2
CMSS 904 Probe Holder..................................................................3-3
Installation instructions for CMSS 904 Probe Holder..................3-3
CMSS 911 Probe Holder with Housing/Dual Sensor Holder
with Housing ......................................................................................3-4
CMSS 911 Probe Holder..................................................................3-4
CMSS 911 Dual Sensor Holder.......................................................3-4
Probe Adapter ....................................................................................3-5
Installation instructions for CMSS 911 Probe Holder with
Housing and CMSS 911 Dual Sensor Holder...............................3-5
CMSS 912 Dual Axial Probe Adapter..............................................3-5
CMSS 61/CMSS 65 Eddy Probe unique installations ..................3-5
Installation instructions for CMSS 912 Dual Axial Probe
Adapter................................................................................................3-6
CMSS 903 Series Mounting Brackets............................................3-7
Mounting devices, adapters and packing glands ..........................3-7
CMSS 903 Mounting Brackets ........................................................3-7
CMSS 903-1 Probe Holders............................................................3-7
CMSS 903-2 Probe Holders............................................................3-7
CMSS 903-3 Probe Holders............................................................3-7
Installation instructions for CMSS 903 Series Mounting
Brackets ..............................................................................................3-8
Mounting and positioning the probes ............................................3-8
Normal and counter motion (Thrust probes)................................3-8
Table of contents
iii
Table of contents

Table of contents
iv
Description Page
Section 5 Optional equipment
Introduction ........................................................................................5-1
CMSS 920 High Pressure Feedthrough.........................................5-1
CMSS 30112000 Series Cable Packing Gland Assembly............5-2
CMSS 30837800 1/2” (12.7 mm) or 3/4” (19 mm) NPT
Probe adapter.....................................................................................5-3
Section 6 Maintenance
Introduction ........................................................................................6-1
Periodic/preventative maintenance.................................................6-1
Calibration...........................................................................................6-1
CMSS 601 Series Static Calibrator.................................................6-1
Description..........................................................................................6-1
CMSS 601-1 and CMSS 601-2 Field Calibrator set-up
procedure............................................................................................6-2
CMSS 601-8 Field Calibrator set-up procedure ..........................6-3
Calibration procedure........................................................................6-4
Probe gap voltage test setup ...........................................................6-5
Troubleshooting notes.......................................................................6-5
Repairs ................................................................................................6-5
Table of contents
Description Page
Section 3 – Probe installation
Normal motion...................................................................................3-8
Setting gap electrically......................................................................3-8
Documentation...................................................................................3-8
Cables and connections ....................................................................3-9
Probe mounting don’ts .................................................................. 3-10
Mounting “Button” eddy probes ................................................... 3-10
Section 4 – Driver installation
Introduction ........................................................................................4-1
CAL adjustment (R1).........................................................................4-1
Probe connector (J1).........................................................................4-1
Terminal strip connectors.................................................................4-1
Electrical..............................................................................................4-1
Power requirements..........................................................................4-2
CMSS 600, CMSS 606 and CMSS 620-2 Drivers.......................4-2
CMSS 665, CMSS 665P, CMSS 668 and CMSS 668P Drivers .4-2
Wiring connections............................................................................4-2
Mounting (Mechanical)......................................................................4-3
Isolation plate for CMSS 600, CMSS 606 and CMSS 620-2
Drivers.................................................................................................4-4
Weatherproof housings ....................................................................4-4
Weatherproof housings (NEMA 4 and 4X).....................................4-4
Weatherproof housings for protection from adverse
environmental conditions.................................................................4-4
Water resistant housings..................................................................4-4
Water and corrosion resistant housing (stainless steel) ..............4-4
Weatherproof housing configurations ............................................4-4
Weatherproof housings for DIN-rail mount drivers.....................4-5
Explosion-proof housings for DIN-rail mount drivers.................4-7
Explosion-proof housings.................................................................4-7
Explosion-proof housings dimensions ...........................................4-7

SKF Reliability Systems
Limited Warranty
WARRANTY
Subject to the terms and conditions contained herein,
SKF warrants to the Buyer that for the warranty period
indicated below the products sold by SKF that are listed
below (the “Products”), when properly installed, maintained
and operated, will be free from defects in material and
workmanship and shall be fit for the ordinary purposes for
which the Products are designed.
BUYER’S LIMITED REMEDIES
This limited warranty defines SKF’s sole and exclusive
liability and Buyer’s sole and exclusive remedy for any claim
arising out of, or related to, any alleged deficiency in any
Product sold by SKF, even if such claim is based on tort
(including negligence or strict liability), breach of contract,
or any other legal theory.
If the Product does not conform to this limited warranty,
Buyer must notify SKF or SKF’s authorized service
representative within thirty (30) days of discovery of the
nonconformity; provided, however, that SKF shall not be
liable for any claim for which notice is received by SKF
more than thirty (30) days following the expiration of the
applicable warranty period for the Product. Upon receipt of
timely notification from Buyer, SKF may, at its sole option,
modify, repair, replace the Product, or reimburse Buyer for
any payment made by Buyer to SKF for the purchase price
of the Product, with such reimbursement being pro rated
over the warranty period.
WARRANTY PERIOD
Except as expressly provided below, the warranty period for
each Product shall commence on the date the Product is
shipped by SKF to Buyer.
90-DAY WARRANTY
Products warranted for ninety (90) days by SKF are
as follows: cable assemblies, MARLIN QuickConnect
(MQC), magnetic temperature probes, and all refurbished
equipment.
Limited Warranty
v
ONE-YEAR WARRANTY
Products warranted for one (1) year by SKF are as follows:
all Microlog products and accessories, all MARLIN data
managers (MDM), all MARLIN Condition Detectors (MCD),
all Wireless Machine Condition Detectors (WMCD), all
Multilog Condition Monitoring Units (CMU, TMU), Multilog
Local Monitoring Units (LMU), all Wireless Monitoring
Systems V/T, all Vibration PenPlus, all transmitters, all SKF
software, all Monitor Interface Modules (MIM), all Machine
Condition Transmitters (MCT), MicroVibe P and Custom
Products with the prefix of CMCP (with the exception of any
consumable or expendable items).
TWO-YEAR WARRANTY
Products warranted for two (2) years by SKF are as follows:
all standard Eddy Probes, Eddy Probe Drivers, and Eddy
Probe Extension Cables, Multilog On-line Monitoring
system (DMx), and all M800A and VM600 Machinery
Monitoring Systems.
For all On-line Systems that have satisfied Criteria 1 and
2 below, the warranty period shall be either thirty (30)
months from the date the On-line System is shipped by
SKF to Buyer, two (2) years from the date the On-line
System is installed and commissioned by SKF, or two (2)
years from the date on which the installation of the On-
Line System has been audited and commissioned by SKF
or its authorized service representative, whichever period
ends first.
Criteria 1. Devices used with a Multilog Condition
Monitoring Unit (CMU), Multilog Local
Monitoring Unit (LMU), including, but not
limited to, the sensing device, the interconnect
cabling, junction boxes, if any, and the
communications interface, must consist only of
SKF-supplied or SKF-approved devices and/or
components. The computer provided by Buyer
must meet the requirements stipulated by SKF.

defects caused by or attributable to the Buyer, including
without limitation Buyer’s failure to comply with any written
instructions provided to Buyer by SKF.
SKF shall be free to conduct such tests, investigations
and analysis of the Products returned to SKF, as it deems
reasonable and proper in the exercise of its sole judgment.
As a further condition to SKF’s obligations hereunder,
Buyer shall offer its reasonable cooperation to SKF in the
course of SKF’s review of any warranty claim, including,
by way of example only, Buyer’s providing to SKF any and
all information as to service, operating history, mounting,
wiring, or re-lubrication of the Product which is the subject
of the Buyer’s warranty claim.
EXCEPT WARRANTY OF TITLE AND FOR THE
WARRANTIES EXPRESSLY SET FORTH IN HEREIN,
IT IS UNDERSTOOD AND AGREED THAT: (a) SKF
MAKES NO OTHER WARRANTY, REPRESENTATION OR
INDEMNIFICATION, EITHER EXPRESS OR IMPLIED,
INCLUDING WITHOUT LIMITATION ANY IMPLIED
WARRANTY OF MERCHANTABILITY, FITNESS FOR A
PARTICULAR PURPOSE, OR NON-INFRINGEMENT; (b)
IN NO EVENT SHALL SKF BE LIABLE OR OBLIGATED
FOR SPECIAL, EXEMPLARY, PUNITIVE, INCIDENTAL,
DIRECT, INDIRECT, GENERAL OR CONSEQUENTIAL
DAMAGES (INCLUDING, BY WAY OF EXAMPLE ONLY,
LOST PROFITS OR SAVINGS, LOSS OF BUSINESS
OR LOSS OF USE) OR ANY OTHER LOSS, COST OR
EXPENSE IN CONNECTION WITH THE PRODUCTS AND
RELATED SERVICES, IF ANY, PROVIDED BY SKF, AND
THIS DISCLAIMER SHALL EXTEND AS WELL TO ANY
LIABILITY FOR NONPERFORMANCE CAUSED BY SKF’S
GROSS OR ORDINARY NEGLIGENCE, AND IN ALL CASES
REGARDLESS OF WHETHER OR NOT ANY OF THE
FOREGOING WERE FORESEEABLE OR THAT SKF WAS
ADVISED AS TO THE POSSIBILITY OF SUCH DAMAGES,
LOSS, COST, OR EXPENSE; AND (c) NO PERSON HAS
BEEN AUTHORIZED BY SKF TO MAKE ANY FURTHER
OR CONTRARY INDEMNITIES, REPRESENTATIONS OR
WARRANTIES ON BEHALF OF SKF. THE FOREGOING
LIMITATIONS AND DISCLAIMERS OF LIABILITY SHALL
BE MADE APPLICABLE TO THE SALE OF ANY PRODUCT
BY SKF TO THE FURTHEST EXTENT PERMITTED BY
APPLICABLE LAW.
The exclusive remedies provided in this limited warranty
shall not be deemed to have failed of their essential
purpose so long as SKF is willing and able to perform to
the extent and in the manner prescribed in this limited
warranty.
® SKF, MARLIN, Microlog and Multilog are registered trademarks of the SKF Group.
CM-F0001 (Revision P, 12-07)
Criteria 2. SKF or its authorized service representative
has installed the On-line System or has audited
the installation and commissioned the On-line
System.
“On-line Systems” are defined as systems consisting of
Multilog Condition Monitoring Unit(s) (CMU), Multilog
Local Monitoring Unit(s) (LMU), and any sensing or input
devices, the interconnect cabling between the sensing
or input devices and the Multilog Condition Monitoring
Unit(s) (CMU), Multilog Local Monitoring Unit(s) (LMU),
and the cabling between the Multilog Condition Monitoring
Unit (CMU), Multilog Local Monitoring Unit (LMU) and the
proprietary SKF communications interface with the host
computer.
FIVE-YEAR WARRANTY
Products warranted for five (5) years by SKF are as follows:
all standard seismic sensors (accelerometers and velocity
transducers).
OTHER SKF PRODUCTS
Any SKF product supplied hereunder but not covered
by this limited warranty shall be either covered by the
applicable SKF limited warranty then in place for such
product or, if no such warranty exists, shall be covered by
the 90-day warranty stated above.
THIRD PARTY PRODUCT WARRANTIES
For any third party products sold to Buyer by SKF, SKF will
transfer to Buyer any warranties made by the applicable
third party product vendor to the extent such warranties
are transferable.
CONDITIONS
As a condition to SKF’s warranty obligations hereunder and
if requested or authorized in writing by SKF, Buyer shall
forward to SKF any Product claimed by Buyer as being
defective. Buyer shall prepay all transportation charges to
SKF’s factory or authorized service center. SKF will bear
the cost of shipping any replacement Products to Buyer.
Buyer agrees to pay SKF’s invoice for the then-current
price of any replacement Product furnished to Buyer by
SKF, if the Product that was replaced is later determined by
SKF to conform to this limited warranty.
SKF shall not be obligated under this limited warranty or
otherwise for normal wear and tear or for any Product
which, following shipment and any installation by SKF
(if required by the contract with the Buyer), has, in
SKF’s sole judgment, been subjected to accident, abuse,
misapplication, improper mounting or remounting,
improper lubrication, improper repair or alteration, or
maintenance, neglect, excessive operating conditions or for
Limited Warranty
vi
SKF Reliability Systems – Limited Warranty (continued)

Section 1
General information
Introduction
This manual provides for the use, installation, and
maintenance information for the following SKF Eddy
Current Probe Systems.
Probe diameter, probe/extension cable/driver
5 mm CMSS 61/CMSS 900/CMSS 606 Series•
8 mm CMSS 60/CMSS 900/CMSS 600 Series•
5 mm CMSS 65/CMSS 958/CMSS 665/CMSS 665P•
Series
8 mm CMSS 68/CMSS 958/CMSS 668/CMSS 668P•
Series
19 mm CMSS 62/CMSS 900/CMSS 620-2 Series•
This manual also explains how to use optional equipment
associated with Eddy Probe Systems.
Eddy Probe Systems are integral components and typically
consist of a non-contacting probe, an extension cable, and
a driver (Figure 1-1).
Figure 1-1. The SKF Eddy Current Probe System.
Driver Powers Probe,
Amplifies and
Linearizes Signal
Eddy Probe
Senses
Movement
Monitor or Detector
Receives Amplified
Signal and Converts
to User’s Needs
Extension Cable
5mm
Displacement
Probe Driver
CMSS 665
-24V GND SIG GND -24V
An Eddy Probe senses mechanical movement and converts
this movement (displacement) into a usable electrical
signal. The signal can then be sent to a monitor system for
conditioning, analysis and/or alarm protection.
Table 1-1. Component compatibility.
Probe Extension
cables Driver System length
CMSS 60
CMSS 60
CMSS 900
CMSS 900
CMSS 600
CMSS 600-1 Series
5 meters
10.5 meters
CMSS 61
CMSS 61
CMSS 61
CMSS 900
CMSS 900
CMSS 900
CMSS 606
CMSS 627
CMSS 606-10
5 meters
9 meters
5 meters
CMSS 62 CMSS 900 CMSS 620-2 10.8 meters
CMSS 65
CMSS 65
CMSS 65
CMSS 65
CMSS 65
CMSS 65
CMSS 958
CMSS 958
CMSS 958
CMSS 958
CMSS 958
CMSS 958
CMSS 665
CMSS 665-1
CMSS 665-8
CMSS 665-16-9
CMSS 665-16-15
CMSS 665-20-00
5 meters
10 meters
5 meters
5 meters
10 meters
5 meters
CMSS 68
CMSS 68
CMSS 68
CMSS 68
CMSS 68
CMSS 68
CMSS 68
CMSS 958
CMSS 958
CMSS 958
CMSS 958
CMSS 958
CMSS 958
CMSS 958
CMSS 668
CMSS 668-1
CMSS 668-2
CMSS 668-8
CMSS 668-16-9
CMSS 668-16-15
CMSS 668-20-00
5 meters
10 meters
15 meters
5 meters
5 meters
10 meters
5 meters
Section 1 – General information
1-1

Table 1-2. Probe compatibility.
Probe CMSS 60 CMSS 61 CMSS 62 CMSS 65 CMSS 68
Case thread 3/8”-24
(M10-1)
1/4”-28
(M8-1)
1”-12
(Not available)
1/4”-28
(M8-1)
3/8”-24
(M10-1)
Tip diameter 8 mm 5 mm 19 mm 5 mm 8 mm
Usable range 90 mil
(2.3 mm)
75 mil
(1.9 mm)
60-300 mil
(1.5-7.6 mm)
80 mil
(2.0 mm)
90 mil
(2.3 mm)
Sensitivity * 200 mV/mil * 200 mV/mil 50 mV/mil 200 mV/mil 200 mV/mil *
Driver CMSS 600 CMSS 606/CMSS 627 CMSS 620-2 CMSS 665 Series CMSS 668 Series
Extension cable CMSS 900 CMSS 900 CMSS 900 CMSS 958 CMSS 958
Overall length †
(Probes) 0.5 to 5.0 meters 0.5 to 3.8 meters 1.0 to 4.0 meters 0.5 to 10.0 meters 0.5 to 15.0 meters
Case lengths 0.8 to 9.0“
(20 to 230 mm)
0.8 to 9.0“
(20 to 230 mm)
1.0 to 5.0“
(25.4 to 127 mm)
0.8 to 9.0“
(20 to 230 mm)
0.8 to 9.0“
(20 to 230 mm)
* 100 mV/mil systems are also available for these two probes.
† Consult factory for other non-standard lengths.
Table 1-3. Driver compatibility.
Driver CMSS 600 CMSS 606 CMSS 620-2 CMSS 665 CMSS 668
Power requirements -18 to -24 Vdc -18 to -24 Vdc -18 to -24 Vdc -24 to -30 Vdc -24 to -30 Vdc
Maximum current
requirements 35 mA 25 mA 35 mA 15 mA 15 mA
Case material Aluminum Aluminum Aluminum RYTON®RYTON®
Output signal Minus voltage Minus voltage Minus voltage Minus voltage Minus voltage
Label color Black Blue Black Blue Black
Reversible terminal
strip No No No Yes Yes
Permanent connection
option Yes Yes Yes Yes, CMSS 665P Series
Yes,
CMSS 668P Series
Output impedance Less than 100 ohms Less than 100 ohms Less than 100 ohms Less than 100 ohms Less than 100 ohms
Section 1 – General information
1-2
Introduction to manual
This manual is a “generic” Eddy Probe Manual. It contains
generalized information for all probes as well as specific
information.
Figures in this manual are for illustrative purposes and
might not be drawn in exact proportion to emphasize
certain items.
Units of measurement are usually in English units with the
metric equivalent in parenthesis.
Initial inspection
The eddy probe and accessories are thoroughly inspected,
mechanically and electrically, before packing for shipment.
However, you should inspect them upon receipt for
shipping damage.
Unpacking
Use care when removing the items from their shipping
container to prevent damage. Save the shipping container
and all packing materials until the items have been
thoroughly inspected for damage and checked for proper
operation.
Equipment furnished
Ensure that each item on the packing list is included with
the shipment. Accessory kit may be shipped in separate
containers.
Inspection for physical damage
Inspect all surface for dents, chips, or scratches. Check for
broken or bent connectors. Photographs of damage are
helpful in substantiating subsequent claims.

Reshipment procedure
If the probe system and/or accessories must be reshipped,
use the original shipping container and packing materials.
If the original packing materials are not available, the
following materials are recommended.
At least 2” (50 mm) of shock absorbing material such as•
ester foam or any other material designed to absorb light
to medium shock loads.
The package should provide protection for “normal”•
handling. For example, a 3 feet (1 meter) vertical drop.
Returned equipment with warranty or damage claims
If the probe system or accessories are damaged in transit
or do not operate as specified when received, notify the
carrier and the nearest SKF Condition Monitoring, Inc.
sales/service office or SKF representative immediately.
Telephone [phone] or 1-858-496-3627. Email
address [e-mail].
The local office will arrange for repair or replacement. SKF
Condition Monitoring, Inc. will assign a Return Material
Authorization (RMA) number to assure identification and
tracking of your equipment.
Selecting an eddy probe system
A wide variety of SKF systems are offered to meet the
requirements of virtually any application. Probe range is
limited largely by the probe’s diameter. The standard SKF
probe diameters are 5 mm (CMSS 65), 8 mm (CMSS 68),
and 19 mm (CMSS 62).
The following should be considered when selecting a
system:
Range
Gap over which the system must accurately operate.
Sensitivity
Must be compatible with monitors or other companion
instruments.
System length
The physical length of the systems is approximate to the
electrical length. Excess cable in certain installations is
typically coiled and tied with no harmful effects.
Probe case
The size of the probe mounting case may be a factor in
some installations.
Section 1 – General information
1-3
Table 1-4. Standard SKF Eddy Probe Systems.
System Usable range Sensitivity System length Standard case Comments
CMSS 60/CMSS 600
CMSS 60/CMSS 600-1
90 mils
90 mils
200 mV/Mil
200 mV/Mil
5 meters
10 meters
3/8-24
3/8-24
Standard length
Long system length
CMSS 61/CMSS 606
CMSS 61/CMSS 627
80 mils
80 mils
200 mV/Mil
200 mV/Mil
5 meters
9 meters
1/4-28
1/4-28
Standard length
Long system length
CMSS 62/CMSS 620-2 60-300 mils 50 mV/Mil 10.8 meters 1”-12 UNF Long range
CMSS 65/CMSS 665
CMSS 65/CMSS 665-1
CMSS 65/CMSS 665-16-9
CMSS 65/CMSS 665-20-00
80 mils
80 mils
45 mils
80 mils
200 mV/Mil
200 mV/Mil
200 mV/Mil
200 mV/Mil
5 meters
10 meters
5 meters
5 meters
1/4-28
1/4-28
1/4-28
1/4-28
Standard length
Long system length
Intrinsically safe
Non-incentive
CMSS 68/CMSS 668
CMSS 68/CMSS 668-1
CMSS 68/CMSS 668-2
CMSS 68/CMSS 668-16-9
CMSS 68/CMSS 668-20-00
90 mils
90 mils
90 mils
65 mils
90 mils
200 mV/Mil
200 mV/Mil
200 mV/Mil
200 mV/Mil
200 mV/Mil
5 meters
10 meters
15 meters
5 meters
5 meters
3/8-24
3/8-24
3/8-24
3/8-24
3/8-24
Standard length
Long system length
Long system length
Intrinsically safe
Non-incentive

Section 1 – General information
1-4
Some eddy probe options
Armor
A flexible stainless steel jacket protects the cable.
Recommended when the cable is not protected by conduit
(such as inside a machine). Available on probe cables and
extension cables.
Certification
Approved probes and drivers can be supplied with
certification tags attached (SIRA, CSA, and FM Factory
Mutual Systems).
A word about . . .
Probe Tips
SKF uses RYTON®for eddy probe tips because it is
simply the best material for the job. RYTON®has high
dimensional stability reducing probe coil shape variations
with temperature and humidity and maintaining system
accuracy, linearity, and resolution. RYTON®is a “super
plastic” that has no known solvent below +400 °F
(+205 °C) and therefore highly resistant to the acids, bases
and solvents handled by process machinery.
Installation
Major considerations include temperatures, pressures, and
mechanical stress to which the probe, driver, and cables are
subjected. It is essential that the probe be rigidly mounted,
yet easily adjusted (SKF mounting accessories are ideal for
this). If long cable runs between the driver and monitor
are required, consult the table in Figure 1-2 to determine
the maximum recommended wire length (use 3-conductor
shielded wire).
Figure 1-2. Wiring distance and system response variances with target
material.
Gap From Probe Tip To Test Article (mils)
Outputs (Vdc)
-22
-20
-18
-16
-14
-12
-10
-8
-6
-4
-2
010 20 30 40 50 60 70 80 90 100
304
Stainless
Steel
4140 Steel
Copper
Sintered Tungsten Carbide
Aluminum
Wire Size
(AWG)
Distance
(Maximum)
22
20
18
16
1,000 Feet
(303 Meters)
2,000 Feet
(606 Meters)
3,000 Feet
(909 Meters)
4,000 Feet
(1,212 Meters)
Target material
Standard systems are calibrated to observe 4140 steel.
As recommended by API Standard 670, probe calibration
should be verified on a target with the same electrical
characteristics as the shaft. The SKF CMSS 601 Series
Static Calibrator and the driver trim control, permit
verification and convenient field calibration within a ±5%
range on the shaft itself. Response is dependent upon
the conductance of the target material, as illustrated in
Figure 1-2. Drivers may be special ordered for calibrated
response to different metal types. Customers will be
requested to provide samples of the metal types. Special
calibration will be “best effort” and is not a guarantee full
linear range will be attained.
Runout
Because the eddy probe works on the principle of
conductivity, shaft irregularities (flat spots, scratches,
plating, hardness variations, carbon inclusions, magnetized
regions, etc.) may produce false vibration signals. API
Standard 670 recommends runout be limited to 0.25 mils
maximum. Some irregularities, such as plated shafts,
cannot be reduced to an acceptable level with traditional
methods (peening, knurling, etc.).
Intrinsic safety
SKF monitors provide current limited power to eddy
probe systems which meet safety requirements of most
applications. However, if intrinsic safety barriers (Zener
barriers) will be used, consult the local sales representative
to ensure range, linearity, and power requirements will be
met.
API Standard 670
The American Petroleum Institute has published Standard
670 as an aid to the procurement of standardized non
contacting vibration, axial position, and temperature
monitoring systems. The standard is based on the
accumulated knowledge and experience of petroleum
refiners and monitoring system manufacturers. API
Standard 670 is a valuable reference tool for all machinery
users and manufacturers, and is highly recommended as
a guide for defining, purchasing, and installing machinery
monitoring systems.
API 670 was written to define reliable protection systems
for rotating equipment operating in the harsh conditions
found in oil production, refining, and chemical processing.
RYTON®based SKF Eddy Current Probes were designed
using a unique temperature chamber to test the probes