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UV Fluorescent Testing or Xenon
Arc Testing….
The Right Choice.
The Right Choice?
QUV Weathering Tester Q-Sun Xenon Tester
No Tester is Perfect for All
Applications.
A tool for improving
product durability,
and for reducing costs.
Weatherability Testing
Choose an accelerated test
method that matches:
• Your Materials
• Their End Use Environment
• The Type of Degradation that Occurs
The Right Choice
• Forces of Weathering
• Technology of UV Fluorescent Testing
• Technology of Xenon Testing
• Decision Criteria
Why Test?
• Meet Specifications
• Avoid Catastrophes
• Enhance Your Reputation
• Verify Supplier Claims
• Improve Product Durability
Why Test?
• Save on Material Costs
• Expand Existing Product Lines
• Enter New Markets
• Outrun the Competition
• Stay Ahead of Regulations
• Verify Customer Complaints
Forces of Weathering
• Sunlight
• Temperature
• Moisture
Spectrum
of
Sunlight
Electromagnetic Spectrum
International Society for Illumination
• CIE Publication #85 Table 4
• (Peak Natural Daylight Standard)
• 0.68 W/m2 @ 340 nm
UV is Only 5% of Sunlight, but
UV Causes Virtually All Polymer
Degradation!
Short Wavelengths
Are More Damaging
250 350 450 550 650
0.0
0.5
1.0
1.5
2.0
Wavelength (nanometers)
Irra
dian
ce
W/m
2/nm
Visible LightUV Region
UV
-A
UV
-B
UV
-C
Summer Sunlight Standard
Effect Of Window Glass
• Ordinary Glass Filters Out
• Wavelengths
• Shorter Than 310 nm
260 280 300 320 340 360 380 400
0.0
0.2
0.4
0.6
0.8
1.0
1.2
Wavelength (nanometers)
Irra
dia
nce
W
/m2
/nm
Direct
T hroughWindow
Glass
Sun ligh t
Filtering Through
Window Glass
Wavelength Regions of UV
UV - C
100 – 280 nm
Found in outer space; Can
cause unnatural damage
UV – B
280 – 315 nm
Includes shortest wavelengths
at earth’s surface: severe
polymer damage; absorbed by
window glass
UV – A
315 – 400 nm
Causes some polymer damage
Different Materials Have
Different Wavelength Sensitivity
Spectral sensitivity, carbonyl formation vs.
wavelength of irradiation,
with dosage of 1 MJ/m2 at each wavelength.
polyamides, change in mass
vs. wavelength of irradiation,
with dosage of 1 MJ/m2 at each
wavelength.
Small Changes
in Formulation
Can Result in Large Differences
in UV Resistance
In a Laboratory Test
Small Shifts in UV Spectrum
Can Result in Large Differences
in Degradation
Short Wavelengths -
Polymer Degradation
Long Wavelengths -
Fading & Color Change
Choose A Laboratory Spectrum
Based On
• Material Sensitivity
• Type of Degradation
• Service Environment
Additional Characteristics
Affect Spectral Sensitivity
• Color
• Thickness
• Stabilization
Higher
Temperatures Often
Increase the Rate of
Degradation
Temperature
Primary
Photochemical Reactions
Are Not
Affected by Heat
Secondary Reactions
Are
Affected By Heat
Effect of Temperature
Oxidation Rate of Polyethylene
Darker Color = Higher Temperature
Fischer and Ketola, 1993
Moisture
Q-Panel’s Time of Wetness Research
Things Are Wet Outdoors Longer
Than You Think
Time of Wetness vs. Rainfall - Miami, FL
Dew, Not Rain
is the Source of
Most Outdoor Wetness
Effect of Moisture
Don’t Underestimate the Effect
of Moisture
• Changes The Rate Degradation
• Changes Mode Of Degradation
With 12 hours Per Day of
Wetness Outdoors,
How can you accelerate
wetness in the Laboratory?
With 12 hours Per Day of
Wetness Outdoors,
How can you accelerate
wetness in the Laboratory?
Increase the Temperature of Wetness.
All Weathering Testers Are
Screening Devices
No Perfect Simulation
The Right Choice?
QUV Weathering Tester Q-Sun Xenon Tester
Fluorescent UV Tester
QUV Accelerated
Weathering
Tester
model QUV/se
Fluorescent UV Lamp
Specimen Holders
0.0
0.2
0.4
0.6
0.8
1.0
1.2
270 290 310 330 350 370 390
Wavelength (nm)
Irra
dia
nc
e W
/m²/
nm
UV-B Lamps
UVA-340 Lamps
0.0
0.2
0.4
0.6
0.8
1.0
1.2
260 280 300 320 340 360 380 400
Wavelength (nm)
Irra
dia
nce
(W
/m²/
nm
)
Sunlight
QUV with UVA-340 lamps
Solar Eye™
Irradiance Control
Automatic
Irradiance
Control
5,600-hour lamps
2-hour lamps
Lamp Aging – Automatic Control
UVB-313 Lamps QUV/se
0.0
0.5
1.0
1.5
270 290 310 330 350 370 390
Wavelength (nm)
Irra
dia
nc
e (
W/m
²/n
m)
Effect of Intensity Control
Intensified 75%
Typical Intensity
Sunlight
UVA-340 Lamps QUV/se
Effect of Irradiance Level
Effect of Irradiance Level
Effect of Irradiance Level
Speed vs. Realism
Increasing the stresses
often decreases correlation
Calibration with AutoCal Radiometer
Fluorescent Lamp Advantages
• Fast results
• Very stable spectrum
• Minimal maintenance
• Simple calibration
• Low cost
QUV Moisture
• Condensing Humidity
• Water Spray
QUV
Schematic
Condensation Advantages
• Identical to natural wetness (dew)
• Elevated temperature = acceleration
• Pure water: condensation process
creates distilled water
• Easy to use
Water Spray Option
Erosion &
thermal shock
ensure parts
get wet
Arwood European Wood Coatings
Research Project
• Participants:
• 10 wood research institutes
• 4 industrial partners: Tikkurila Oy,
Gori-Dyryp, ICI Paints Inc., Cecil
• Objective:
• Quickly assess the durability of
exterior wood coatings to meet
environmental issues
• Develop accelerated test device
for small-medium size companies
Requirements
Arwood
QUV/spray: simulate effects of
sunlight, increase moisture
content of wood, produce surface
erosion & degrading of material
Cycle:
Condensation - 24h 45ºC
Light - UVA-340 2.5h 60ºC
Spray - In Darkness 48h
Duration - 2016 hours
Solution
Basis for proposed revision to
CEN test method Pr ENV 927-6
“Paints & Varnishes - Coating
Systems for Exterior Wood”
State of the Art Fluorescent UV
Tester: QUV
• Irradiance Control
• Calibration with AutoCal
Radiometer
• Self-diagnostic
• Ethernet Capabilities
Making The Right Choice
QUV Weathering Tester Q-Sun Xenon Tester
Rotating Drum Schematic
Flat Array Schematic
Uniformity
Advanced Flat Array geometry gives
uniformity comparable to Rotating Drum
testers
Xenon Lamp Cooling
• Operate at high wattage & high intensity
• Lamps generate considerable heat
• Lamps must be cooled
• There are two methods of lamp cooling
• Water-cooled
• Air-cooled
Water-Cooled Xenon Lamp and
Filters
Air Cooled Lamp
0.0
0.5
1.0
1.5
2.0
2.5
3.0
250 300 350 400 450 500 550 600 650 700 750 800
Wavelength (nm)
Irra
dia
nc
e (
W/m
²/n
m)
Q-Sun with
Daylight Filter
QUV with
UVA-340 Lamps
Sunlight
QUV, Xenon, Sunlight...
Xenon Arc Spectra Choices
• Effect of Filters
• Irradiance Control
Filter Selection Summary
• Simulate Service Environment
• Consider Material Spectral
Sensitivity
Filters Alter Xenon Spectrum
Daylight Filters
(exterior exposures)
Extended UV
(auto specs., fast results)
Window Glass
(indoor exposures, textiles, inks, etc.)
Window Glass Daylight
Q-Sun Filters
SPD's of Q-Sun and UVA-340 Lamps vs. Sunlight
0.0
0.5
1.0
1.5
2.0
2.5
3.0
250 300 350 400 450 500 550 600 650 700 750 800
Wavelength (nm)
Irra
dia
nc
e (
W/m
²/n
m)
Xenon With Daylight Filters
Sunlight
Xenon with
Daylight Filter
0.0
0.2
0.4
0.6
0.8
1.0
1.2
260 280 300 320 340 360 380 400
Wavelength (nm)
Irra
dia
nc
e (
W/m
²/n
m)
Xenon with Daylight Filters
Xenon with
Daylight Filter
Sunlight
Xenon with Extended UV Filters vs. Sunlight
0.0
0.5
1.0
1.5
2.0
2.5
3.0
200 300 400 500 600 700 800
Wavelength (nm)
Irra
dia
nc
e (
W/m
2/n
m)
Sunlight
Xenon with Extended UV Filter
0.0
0.2
0.4
0.6
0.8
1.0
1.2
260 280 300 320 340 360 380 400
Wavelength (nm)
Irra
dia
nc
e (
W/m
²/n
m)
Xenon with Extended UV Filters
Xenon with
Extended
UV Filter
Sunlight
0.0
0.5
1.0
1.5
2.0
2.5
3.0
250 300 350 400 450 500 550 600 650 700 750 800
Wavelength (nm)
Irra
dia
nc
e (
W/m
²/n
m)
Xenon with Window Glass Filters
Xenon with Window
Glass Filter
Sunlight
Through
Window Glass
Sunlight
0.0
0.2
0.4
0.6
0.8
1.0
1.2
260 280 300 320 340 360 380 400
Wavelength (nm)
Irra
dia
nc
e (
W/m
²/n
m)
Xenon with Window Glass Filters
Sunlight
Sunlight Through
Window Glass
Xenon with
Window
Glass Filter
Irradiance Control
• Control Intensity
• Select Control Points
• @ 340 nm
• @ 420 nm
• 285-400 nm (TUV)
Irradiance Intensity
• Wide Range
• Dependent on Filter Configuration
• Control Point
• Irradiance Control
• Feedback Loop Control
• Light sensor
• Control module
• Xenon arc lamp
0.0
0.5
1.0
1.5
2.0
2.5
3.0
250 300 350 400 450 500 550 600 650 700 750 800
Wavelength (nm)
Irra
dia
nce (
W/m
²/n
m)
Sunlight
Xenon with Daylight Filter
.68 @ 340 nm Control Point
340 nm Control Point
0.0
0.2
0.4
0.6
0.8
1.0
1.2
260 280 300 320 340 360 380 400
Wavelength (nm)
Irra
dia
nce (
W/m
²/n
m)
340 nm
Control Point
Xenon with Daylight Filter
Sunlight
.68 @ 340 nm Control Point
0.0
0.3
0.5
0.8
1.0
1.3
1.5
1.8
2.0
2.3
2.5
250 300 350 400 450 500 550 600 650 700 750 800
Wavelength (nm)
Irra
dia
nc
e (
W/m
2/n
m)
Xenon with
Window Glass
Filter
Sunlight
through window glass
1.10 @ 420 nm Control Point
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
260 280 300 320 340 360 380 400 420 440 460 480 500 520 540
Wavelength (nm)
Irra
dia
nc
e (
W/m
²/n
m)
Xenon with Window Glass Filter
1.10 @ 420 nm Control Point
Sunlight Through
Window Glass
Lamp Aging
0.0
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
280 300 320 340 360 380 400 420
Wavelength (nm)
Irra
dia
nce (
W/m
2/n
m)
0 hour lamp
1500 hour lamp
Sunlight
through glass
420 nm
control point
1.10 W/m2 @ 420nm with Window Glass Filter
Temperature Control with Black
Panel Temperature Sensor
Temperature & Color
Fischer and Ketola, 1993
Chamber Air
Temperature Control
• Required by certain Test Methods
• Necessary to control RH
• Requires advanced Technology to achieve
simultaneous control of Black Panel Temp
and Chamber Air Temp
Water Spray
Spray System for
Xenon Requires
Extremely Pure
Water Input
Q-Sun Spray System
• Single Water Spray
• Dual Spray
• Acid Etch Simulation
• Specialty Solutions
State of the Art Xenon Arc
Tester: Q-Sun
• Irradiance Control
• Choice of Filters
• Calibration with AutoCal
Radiometer
• Simultaneous Control of
Black Panel Temp,
Chamber Air Temp, and
Relative Humidity
QUV
• UVA-340 best simulation
of shortwave UV
• UVB-313 might be too
severe
• No visible light
• Stable spectrum
• Irradiance control
• No RH control
• More aggressive moisture
attack
• Full spectrum
• Best simulation of long
wave UV & visible light
• Spectrum changes over
time
• Irradiance control
• Relative humidity control
• Water spray options
XENON
QUV Is The Most Cost Effective
For Polymer Degradation
• Gloss loss
• Yellowing
• Chalking
• Checking
• Cracking
QUV Is More Realistic For Water
Sensitive Materials
Xenon is best for materials
damaged by visible light
• Indoor end use (furniture lacquer)
• Printing Inks
• Organic Pigments
Xenon is More Realistic For
Testing Lightfastness / Color
Degradation
Choose an accelerated test
method that fits your materials,
their end use environment,
and the type of degradation that
occurs.
A Compromise Used by Many Labs
• Use a QUV for most testing
• Use a small Xenon for color change.