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EJAM7-3NT72 A New Mechanical Condition-based Maintenance Technology Using Instrumented Indentation Technique
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(in English)

Vol.1 No.4 previous GA 11 - 12 - AA SP1 ( 11 - 12 - 13 - 14 ) - NT 19 - 20 - 21 - 22 next Vol.2 No.2
Vol.2, No.1, NT20 EJAM (1-4-NT20) -"WearMATE"Portable Ferrograph Analyzer for Wear Debris Diagnosis

"WearMATE" Portable Ferrograph Analyzer for Wear Debris Diagnosis

The Tokyo Electric Power Co., Inc. and TRIBOTEX Co., Ltd.

CBM (Condition Based Maintenance), Wear Condition Analysis, Debris Diagnosis, Portable Ferrograph, Condition Monitoring, Wear Particle, Ferrography

1. Technical summary
(I: Inspection, II: Repair, III: Replacement, IV: Preventive Maintenance, V: Others)
Ferrography is the one of Wear Analysis method which is given at Laboratory. "WearMATE" has been developed as a Ferrography device to diagnose the wear condition of equipments at an actual site by using circular magnetic gradient and centrifugal force.
Fig.1 WearMATE’s rotary part
It arranges magnetic wear debris in circularly-dispose in order of its size on a glass plate automatically and divided into "PL" and "PS". They are flowed by centrifugal force from the center to the outer of the glass plate which lies over a magnet. Larger particles (PL) in the oil, being strongly attracted to the magnet, deposit at closer of the centre part. Smaller particles (PS), being weakly attracted to the magnet, deposit equally along the distance from the centre of the strength of the centrifugal force.

The particles' photo is taken by the Optical Microscope which is equipped Transmitted light, Incident-light and a CCD Camera. The particles in the sample oil are examined its shape and surface condition.

The particles on the glass plate are also given a heat treatment to gain its temper color. By analyzing the temper color, the materials of the particle are identified. These analyses are called "Qualitative Analysis".
EJAM2-1NT20-Fig.2_1_Wear_Particle-Alignment Particle Photo at PS Position Particle Photo at PL Position
EJAM2-1NT20-Fig.2_2_Particle_Photo_at_PS_Position EJAM2-1NT20-Fig.2_3_Particle_Photo_at_PL_Position
Binary Image Binary Image
Wear Particle Alignment
EJAM2-1NT20-Fig.2_4_Binary_Image EJAM2-1NT20-Fig.2_5_Binary_Image
EJAM2-1NT20-Fig.2_1(1)_PS_Small_Particle PS: Small Particle

EJAM2-1NT20-Fig.2_1(2)_PL_Large_Particle PL: Large Particle
Fig.2 Data Plate (Ferrogram)
The plate (Ferrogram) is analyzed and diagnosed quantitatively by dedicated software at first. Then the particles are projected its shadow by using only transmitted light and it is manipulated as a binary image. The software analyzes this image and calculates "Is" (Severity Index) 【5】degree to provides analysis results. These analyses are called "Quantitative Analysis"

WearMATE provides Wear Trend Monitoring without the objective machine stops by using these two analyses above. Moreover, it makes possible to plan an appropriate maintenance plan and reduce its cost.
EJAM2-1NT20-Fig.3_Wear_Condition_Table_&_Is_Calculation EJAM2-1NT20-Fig.3_Wear_Condition_Table_&_Is_Calculation
Severity Index ;Is
Is = (PL + PS)( PL - PS)
= PL2- PS2

(PL+PS): Total Amount of Wear Particle
(PL-PS): Degree of Abnormal Wear

PL(%/ml):Large Particle (Large Wear Particle)
PS(% /ml):Small Particle (Small Wear Particle)
Fig.3 Wear Condition Table & Is Calculation
2. Scope
(1) Components
Bearings of generator (Steam/Gas/Water/Wind Turbine), Engine (D/G, Marine), Gear Box, Windlass (Warm Gear), Pump, Fan, Compressor, Motor, etc.

(2) Materials
Ferrous Particle, (Non-Ferrous Particle is also possible to be captured with deposition on the glass by using Gravity Force, but it may not be able to catch all)
3. Features
(1) Portable Analysis Device
The device realizes the machinery wear condition diagnosis at actual sites which have a restriction of taking oil to outside.

(2) Wear Trend Monitoring
The software holds the analysis history and it can provide the wear condition degree.
4. Examples of Application
The device is actually being used at some Nuclear Power Plants in Japan for monitoring the wear condition of their equipments.
5. Reference
[1] N. Miyata, M. Kawabata, Y. Sasaki, and T. Kamiya, "ICIT2006 Indian Institute of Science Bangalore, India" P.125
[2] N. Miyata, M. Kawabata, Y. Sasaki, and T. Kamiya, "Japan Society of Maintenology 5th Annual Meeting Mito, Japan" P.67
[3] Kenichi Oyama, Tokyo Electric Power Co., Inc and N. Miyata, M. Kawabata, and T. Kamiya, TRIBOTEX Co., Ltd. "Inspection Engineering 2009 May issue" P.28-33
[4] Japan Patent 3626744
[5] JEAG4222-2008 Guide for Predictive Maintenance at Nuclear Power Plant - Oil Analysis
6. Contact
Japan Society of Maintenology (