Thermal Imaging in your Maintenance Program: Intermediate Infrared Concepts and Best Practices
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Transcript of Thermal Imaging in your Maintenance Program: Intermediate Infrared Concepts and Best Practices
Intermediate Infrared Concepts and Best Practices: Thermal Imaging in your Maintenance ProgramSat SandhuThermography Services Support Manager
Thermal / Infrared Thermography, Level III Certified in compliance with (ASNT) SNT-TC-1A-2006
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• Review and introduction to Thermal imaging
• The basics of performing an inspection with an infrared camera
• Tips on how to effectively spot issues with an infrared camera
• Causes and examples of Electrical, Mechanical, Process and Building Diagnostics
• How to tie infrared inspections into your preventative maintenance program
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Agenda
My name is Sat Sandhu Welcome!
Please note, this is a short class – you will not become a thermography expert in the next hour
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Introduction
• Infrared radiation can be sensed by our skin, yet cannot be seen by our eyes!
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What is infrared?
• Infrared cannot be seen (but can be sensed by our skin)
• Everything emits infrared radiation• A camera converts the “infrared
image” to a visible picture• Infrared allows you to “see” things that
you normally can’t
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What is a Thermal Image?
Visual image
Same image in infrared
• Thousands of IR temperature measurements taken• Each “pixel” represents a temperature measurement• Assigned a color value to create an image
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How is an infrared image created?
• Most electrical and mechanical defects cause increase in temperature
• Thermal imaging provides a fast and clear picture of this temperature increase
• Safety: Thermal images can be taken while production is running without any contact
• Anybody can take a picture!
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How can infrared help me?
• Electrical• Mechanical• Process Manufacturing• Building Diagnostics• R&D• Utilities
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Thermal Imaging Applications
• Ensure adequate thermal gradients• Understand thermal capacitance• Account for wind effects• Avoid angular variations• Remember heat transfers from hot to
cold• Be aware of your surroundings• Know when qualitative
measurements are sufficient• Compare similar components under
similar conditions
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Thermal Imaging Considerations
• Understand present and future loading conditions• Inspect with highest load possible (at least 40%)
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Thermal Imaging Considerations
• Objects and materials with high thermal capacitance take time to cool down, while objects and materials with low thermal capacitance cool down quickly
– Air has low thermal capacity, water has high thermal capacity
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Heat Capacity
On a flat roof, after the sun goes down, dry insulation cools faster than wet insulation
(wet insulation has higher thermal capacity)Thermal capacitance can help find
the liquid level in a tank
How far can I see?
Distance from CameraL1 M4
L1 M4
Spot Size & Resolution
• Larger area for average temperature when further away
• Distance to spot ratio• Zoom lens decreases
spot size
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Spot Size & Resolution
• Emissivity • Understand the equipment• Load conditions• Comparative inspections• Hot spots• Cold spots
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TIPS: How to Effectively Spot Issues with an Infrared Camera
This can of suds is ice cold straight out of the fridge. When scanned with the IR Camera you would expect the entire image to be relatively even in temperature and to appear “cold” in relation to the background. What is causing the spot in the center to appear warm?
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What happened to my beer!?
Everything in nature emits electromagnetic radiation. Emissivity is the ratio of thermal energy emission of the target object, over the thermal energy emission of a true blackbody (perfect emitter).
The paint on the outside of this can has been worn off in a small area. The bare aluminum has a different emissivity than the painted aluminum. The imager sees the bare aluminum as hotter than the rest of the can.
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Emissivity!
TIP: Use Electrical Tape to cover a low emissive surface to increase the emissivity and accuracy of the measurement
• Unbalanced loads• Harmonics (3rd harmonic current in
Neutral)• Overloaded systems/excessive
current• Loose or corroded connections
increased resistance in the circuit • Insulation failure• Component failure• Wiring mistakes• Underspecified components
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Causes of Electrical Hot Spots
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Examples of Electrical Hot SpotsHot phase
Fuse disconnect
Substation
Lighting Circuit
Motor Control Center
Buss
• Bad cooling because of reduced airflow• PQ problems like unbalance, overload or 5th harmonic (voltage) • Insulation problems with motor windings• Bearing problems – lubrication, wear, tolerance• Bad alignment
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Causes of Mechanical Hot Spots
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Examples of Mechanical Hot Spots
Compressors - normal
Hydraulic pumps Misaligned beltElectric motor
Roller bearingsCoupling
• Damaged structures caused by worn pipes• Abnormal heat flow/heat gradients• Defective valves/traps• Normal tank level fluctuations
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Causes of Process Hot Spots
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Examples of Process Hot Spots
Weld cooling
Tank Levels
119.7°C
302.2°C
150
200
250
300
Steam TrapsCement Kiln
Pipe IntegrityChiller Operation
• Roof leaks• Air Leak• In-floor heating• Missing insulation
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Causes of Building Diagnostics Hot Spots
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Examples of Building Diagnostics Hot Spots
Roof deck moisture
In-floor heat verification
Missing insulationMoisture
Air Leak Attic access – air leak
• Trends
• Maintenance programs
• Cost Savings
• Solutions
• Build a Successful program
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How to Tie Infrared Inspections into your Preventative Maintenance Program
Downtime is getting more expensive – maintenance must do more with less
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Trends in Industrial Maintenance
Companies are using maintenance best practices to reinforce and extend their competitive advantages
Awareness is growing quickly
New maintenance technologies are experiencing mass adoption
ECONOMICS AWARENESS TECHNOLOGY
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Definitions
Preventive (PM):
“calendar-based”
Predictive (PdM): “condition-based”
Time
Normal Operation Wear OutBreak In
The Bathtub Curve
Casualties
Reactive: “run to failure”
Proactive
Reliability Centered: “asset uptime based”
1. EPRI – study of many plants in many different industries•A comprehensive study by the Electric Power Research Institute found:
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Examples of Cost Savings
Maintenance practices
Cost to maintain rotating machinery
Cost savings
Plants that are Reactive (Run to failure)
$17/HP/Year No savings
Plants that are Preventive (Calendar-based)
$13/HP/Year 24% over Reactive
Plants that are Predictive (Condition-based)
$9/HP/Year 47% over Reactive
2. Cost to Benefit Studies•A large company implemented a Predictive Maintenance program on hundreds of their motors, pumps, fans, compressors and blowers•This program has been successful for over 25 years•They document the cost of the program and savings they enjoy•Savings were many millions of dollars per year•Every 2 years they conduct a Cost to Benefit study to compare the program cost to the documented savings•The average Cost to Benefit ratio for the past 30 years has been over 20:1
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Examples of Cost Savings
The 6 benefits that they track include: •Prevention of catastrophic failure due to early detection•Ability to schedule repairs during plant shutdown periods•Ability to order parts in advance of repairs•Ability to repair exact fault instead of complete overhaul or replacement•Planning of workers schedules•Root cause analysis of recurring faults
3. Case Study – even small companies can benefit
•Over a 16 year period, a small company transitioned from Reactive to Preventive and then to Predictive Maintenance:
– Unplanned failures dropped to almost zero– Maintenance budget, on the 600 critical motor/pumps, cut in half
from 10 years ago– Pumps running twice as long before repairs are needed– Almost all maintenance is scheduled instead of reacting to
emergencies– Repairs planned during the day and eliminating the need for
overtime
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Examples of Cost Savings
• Predictability: give maintenance staff time to schedule repairs
• Safety: take faulty equipment offline
• Revenue: fewer unexpected failures prevent production stoppages that cut into bottom line
• Increased maintenance intervals: life of equipment is extended
• Reliability: anticipate the problems coming
• Peace of mind: build confidence in maintenance schedules, budgeting, and productivity estimates
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Benefits of Proactive Maintenance
Different industries / companies will have different matrixes and targets. Which of these benefits is most valuable to you?
• Ideal: Dedicated PdM or reliability team at a large industrial plant
– People, time and budget to do proactive work
– Uses automated systems/CMMS
– Determines when equipment needs maintenance to prevent failure
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Solution: Asset Uptime for the Rest of Us
Technology is leveling the playing field for maintenance technicians across facilities of all sizes: they can use the same techniques and tools to troubleshoot
as well as to inspect, log, and share – the basics of proactive maintenance
• The rest of us: Small maintenance team at mid-sized industrial or large commercial facility with
– No dedicated people – Broad responsibilities but not
the scope or budget to go full SCADA
– Gather data by hand as the job dictates
Don’t try to do the whole plant at once•Start with simple machines with common problems•Use simple check lists before moving to electronic programs•Show success in early wins, gain buy-in and support to grow program•Proactive maintenance measurements aren’t that different from troubleshooting tests – only faster, easier, and no expert is needed
Simple steps•Take “good” baseline data points – compare over time to good baseline•Quick periodic inspections with screening tools to find problems•Return with smart diagnostic tools – find fault and diagnose repair action•Repair fault with smart corrective tools – fix it quickly & return to service•Validate repair with screening tool
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Program Start-up: Start Small and Grow
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Basic Inspection Guideline
Schedule inspection under load
Thermal Image
Any Anomaly
observed?
Equipment on or
Loaded?
Equipment on or
Loaded?
Equipment on or
Loaded?
Temperatures on target, similar to each other, and
c/f with ambient?
Temp. difference c/f stds.
Identify the type of anomaly:1.Hot spot?2.Cold Spot?3.Temp. difference between similar components?
No Further Action
Extra info / Advice
process
Repair / Action
No
Yes
Yes
No Low
Low
Low
High
High
HighHigh
Low
Medium
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A Program Builds the Links in a Maintenance Chain
Multiple tools equal more than the sum of the parts
Alignment Tool
Problem corrected
Vibration Tester Vibration Tester
Problem identified & repair recommended
Machine checked with vibration meter
Thermal Imager
Problem found with vibration meter
SCAN DIAGNOSE FIX VALIDATE
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Technologies & Solutions – Multiple Tools
Thermography Mechanical Electrical Process
Infrared Imager Vibration and Alignment
ScopeMeter and Power Quality
Insulation Tester
Process Tools
Best technology for finding electrical hot spots in switchgear & motor controllers, screening process and mechanical
Best technology for diagnosing mechanical faults in rotating machines. Correct shaft misalignment.
Troubleshoot problems in drive and drive output, power distribution - uncover energy losses & efficiency
Assures safe operation, prolongs life of electrical systems & motors
Troubleshoot, commission and calibrate transmitters, valves, switches, gauges
1. Faulty connections
2. Overheated bearings
3. Tank levels
1. Imbalance 2. Looseness 3. Misalignment 4. Bearings
1. Harmonics2. Distortion3. Load Studies
Insulation degradation
1. Pressure2. Temperature3. mA source
• I want to see a camera? • I want to learn more about thermal imaging?• I want an IR camera? • I want to talk about my specific application?
• We have 2 certified Level I thermographers on staff– Ben Goodhead– Susan Garofalo
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Before we dismiss…
Questions or Comments?Email Nicole VanWert-Quinzi
Transcat: 800-800-5001www.Transcat.com
For related product information, go to: www.Transcat.com/Fluke