SIST-TS CEN/TS 16599:2014
(Main)Photocatalysis - Irradiation conditions for testing photocatalytic properties of semiconducting materials and the measurement of these conditions
Photocatalysis - Irradiation conditions for testing photocatalytic properties of semiconducting materials and the measurement of these conditions
CEN/TR 16599 prescribes the conditions for irradiating photocatalytic surfaces in order to perform photocatalytic efficiency tests. In addition, the measurement and documentation of these irradiation conditions with respect to the spectral distribution, irradiance and homogeneity are given.
Photokatalyse - Bestrahlungsbedingungen zum Prüfen photokatalytischer Eigenschaften von halbleitenden Werkstoffen und die Messung dieser Bedingungen
Diese Technische Spezifikation legt die Bestrahlungsbedingungen für photokatalytische Oberflächen fest, um photo¬katalytische Wirksamkeitsprüfungen durchzuführen. Zusätzlich sind die Messung und Dokumentation dieser Bestrahlungsbedingungen hinsichtlich der Spektralverteilung, Bestrahlungsstärke und Homogenität festgelegt.
Photocatalyse - Détermination des conditions d’irradiation pour tester les propriétés photocatalytiques de matériaux semi-conducteurs
La présente Spécification technique prescrit les conditions d’irradiation des surfaces photocatalytiques dans le but de réaliser des essais d’efficacité photocatalytique. La détermination et la documentation de ces conditions d’irradiation, telles que la répartition spectrale, l’éclairement énergétique et l’homogénéité, sont également indiquées.
Fotokataliza - Obsevalni pogoji za preskušanje fotokatalitičnih lastnosti polprevodnih snovi in meritve teh pogojev
Standard CEN/TR 16599 predpisuje pogoje obsevanja fotokatalitičnih površin z namenom izvajanja fotokatalitičnih preskusov učinkovitosti. Poleg tega so v standardu podane meritve in dokumentacija pogojev obsevanja glede na spektralno porazdelitev, obsevanje in homogenost.
General Information
Standards Content (Sample)
SLOVENSKI STANDARD
SIST-TS CEN/TS 16599:2014
01-junij-2014
)RWRNDWDOL]D2EVHYDOQLSRJRML]DSUHVNXãDQMHIRWRNDWDOLWLþQLKODVWQRVWL
SROSUHYRGQLKVQRYLLQPHULWYHWHKSRJRMHY
Photocatalysis - Irradiation conditions for testing photocatalytic properties of
semiconducting materials and the measurement of these conditions
Photokatalyse - Bestrahlungsbedingungen zum Prüfen photokatalytischer Eigenschaften
von halbleitenden Werkstoffen und die Messung dieser Bedingungen
Photocatalyse - Détermination des conditions d’irradiation pour tester les propriétés
photocatalytiques de matériaux semi-conducteurs
Ta slovenski standard je istoveten z: CEN/TS 16599:2014
ICS:
25.220.20 Površinska obdelava Surface treatment
SIST-TS CEN/TS 16599:2014 en,fr,de
2003-01.Slovenski inštitut za standardizacijo. Razmnoževanje celote ali delov tega standarda ni dovoljeno.
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SIST-TS CEN/TS 16599:2014
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SIST-TS CEN/TS 16599:2014
TECHNICAL SPECIFICATION
CEN/TS 16599
SPÉCIFICATION TECHNIQUE
TECHNISCHE SPEZIFIKATION
March 2014
ICS 25.220.20
English Version
Photocatalysis - Irradiation conditions for testing photocatalytic
properties of semiconducting materials and the measurement of
these conditions
Photocatalyse - Détermination des conditions d'irradiation Photokatalyse - Bestrahlungsbedingungen zum Prüfen
pour tester les propriétés photocatalytiques de matériaux photokatalytischer Eigenschaften von halbleitenden
semi-conducteurs Werkstoffen und die Messung dieser Bedingungen
This Technical Specification (CEN/TS) was approved by CEN on 14 October 2013 for provisional application.
The period of validity of this CEN/TS is limited initially to three years. After two years the members of CEN will be requested to submit their
comments, particularly on the question whether the CEN/TS can be converted into a European Standard.
CEN members are required to announce the existence of this CEN/TS in the same way as for an EN and to make the CEN/TS available
promptly at national level in an appropriate form. It is permissible to keep conflicting national standards in force (in parallel to the CEN/TS)
until the final decision about the possible conversion of the CEN/TS into an EN is reached.
CEN members are the national standards bodies of Austria, Belgium, Bulgaria, Croatia, Cyprus, Czech Republic, Denmark, Estonia,
Finland, Former Yugoslav Republic of Macedonia, France, Germany, Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania,
Luxembourg, Malta, Netherlands, Norway, Poland, Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and United
Kingdom.
EUROPEAN COMMITTEE FOR STANDARDIZATION
COMITÉ EUROPÉEN DE NORMALISATION
EUROPÄISCHES KOMITEE FÜR NORMUNG
CEN-CENELEC Management Centre: Avenue Marnix 17, B-1000 Brussels
© 2014 CEN All rights of exploitation in any form and by any means reserved Ref. No. CEN/TS 16599:2014 E
worldwide for CEN national Members.
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Contents Page
Foreword .3
Introduction .4
1 Scope .5
2 Symbols and abbreviations .5
3 Specification of spectral areas and irradiance values .5
4 Lamp types and filters .6
4.1 Examples of different lamp types .6
4.1.1 Xenon lamps .6
4.1.2 Halogen lamps .7
4.1.3 Fluorescence lamps .7
4.1.4 Mercury vapour lamps .7
4.1.5 Light emitting diodes (LED) .8
4.1.6 Sunlight .8
4.2 Controlling of the ageing behaviour of the used lamp .8
4.3 Filters .8
4.3.1 Cut-on/Cut-off-filters for irradiation of large areas .8
4.3.2 Band-pass-filters for irradiation of small areas .8
4.3.3 Interference filters.9
5 Diffusers .9
6 Measuring systems .9
6.1 General .9
6.2 Thermopile-Sensors . 10
6.3 Calibrated Si-Photodiodes . 10
6.4 Quantum counter based on fluorescence . 11
6.5 Chemical actinometry . 11
6.6 Spectral radiometers . 11
7 Homogeneous irradiation of areas . 11
7.1 Homogeneity of intensity . 11
7.2 Number and local positions of the measurement points . 12
7.3 Position of the measurement plane . 13
8 Test report . 14
Annex A (informative) Informative examples and definitions. 15
A.1 Informative Terms and definitions . 15
A.1.1 Standard irradiation conditions . 15
A.1.2 Irradiation conditions for specific applications . 15
A.2 Examples for available cut-on-filters . 16
A.3 Examples for available band-pass-filters . 17
A.4 Examples for available light emitting diodes (LED) . 18
A.5 Example of different angle distribution of various diffusor types . 19
A.6 Examples for spectra of different fluorescence tubes. 19
Bibliography . 21
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Foreword
This document (CEN/TS 16599:2014) has been prepared by Technical Committee CEN/TC 386
“Photocatalysis”, the secretariat of which is held by AFNOR.
Attention is drawn to the possibility that some of the elements of this document may be the subject of patent
rights. CEN [and/or CENELEC] shall not be held responsible for identifying any or all such patent rights.
CEN (the European Committee for Standardization) is a European committee of national standards bodies
(CEN member bodies). The work of preparing European Standards is normally carried out through
CEN Technical Committees. Each member body interested in a subject for which a Technical Committee has
been established has the right to be represented on that committee.
European organizations, governmental and non-governmental, in liaison with CEN, also take part in the work.
The main task of Technical Committees is to prepare European Standards. Drafts adopted by the Technical
Committees are circulated to the member bodies for voting. Publication as a European Standard requires
approval by at least 71 % of the member bodies casting a vote.
Safety statement
Persons using this document should be familiar with the normal laboratory practice, if applicable. This
document cannot address all of the safety problems, if any, associated with its use. It is the responsibility of
the user to establish appropriate safety and health practices and to ensure compliance with any regulatory
conditions.
Environmental statement
It is understood that some of the material permitted in this standard may have negative environmental impact.
As technological advantages lead to better alternatives for these materials, they will be eliminated from this
standard to the extent possible.
At the end of the test, the user of the standard will take care to carry out an appropriate disposal of the
wastes, according to local regulation.
According to the CEN-CENELEC Internal Regulations, the national standards organizations of the following
countries are bound to announce this Technical Specification: Austria, Belgium, Bulgaria, Croatia, Cyprus,
Czech Republic, Denmark, Estonia, Finland, Former Yugoslav Republic of Macedonia, France, Germany,
Greece, Hungary, Iceland, Ireland, Italy, Latvia, Lithuania, Luxembourg, Malta, Netherlands, Norway, Poland,
Portugal, Romania, Slovakia, Slovenia, Spain, Sweden, Switzerland, Turkey and the United Kingdom.
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Introduction
Photocatalysis is a very efficient advanced oxidation technique which enables the production of hydroxyl
radicals (∙OH) or perhydroxyl radicals (∙OOH), capable of partly or completely mineralising/oxidising the
majority of organic compounds. Its principle is based on the simultaneous actions of photons and of a catalytic
layer which allows degradation of molecules. The most commonly used photocatalyst is titanium dioxide
(TiO ), the latter being thermodynamically stable, non-toxic and economical. It can be used in powder form or
2
deposited on a substrate (glass fibre, fabrics, plates/sheets, etc.). The objective is to introduce performance
standards for photo-induced effects (including photocatalysis). These standards will mainly concern test and
analysis methods.
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1 Scope
This Technical Specification prescribes the conditions for irradiating photocatalytic surfaces in order to
perform photocatalytic efficiency tests. In addition, the measurement and documentation of these irradiation
conditions with respect to the spectral distribution, irradiance and homogeneity are given.
2 Symbols and abbreviations
APD avalanche photodiode
A (λ)
decadic absorbance
CA chemical actinometry
E
irradiance
FWHM full width at half maximum
h
height difference
d
h maximum height difference
max
h
measurement plane
s
LED light emitting diode
PC-A photocatalytic amber
PC-B photocatalytic blue
PC-C photocatalytic cyan
PC-G photocatalytic green
PC-R photocatalytic red
PC-U photocatalytic ultraviolet
PC-UC photocatalytic ultraviolet C
PC-V photocatalytic violet
QP (λ) total amount of absorbed photons
abs
q ° (λ) incident photon flux
p
λ wavelength
φ (λ) quantum yield
In Annex A, further examples concerning literature, terms and definitions, quantities and figures are listed for
information.
3 Specification of spectral areas and irradiance values
As shown in Table 1, different spectral areas in combination with the specified irradiance should be used for
irradiation during photocatalytical analysis. The test procedures themselves are described in their according
standards, e.g. ISO 22197-1 [6] for the abatement of nitrogen monoxide.
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Table 1 — Specification of spectral areas and irradiance values
a
Cut-off-Lim
Cut-on-Limit Irradiance
Range Abbreviation Colour Peak FWHM it
max
E < 2 %
E < 5 %
2
nm nm nm nm W/m
UV not
PC-UC Ultraviolet C 254 ± 5 not defined not defined not defined
defined
10,0
PC-U Ultraviolet 365 ± 5 20 345 385
(± 10 %)
VIS PC-V Violet 405 ± 5 15 370 440 9,0 (± 7 %)
PC-B Blue 450 ± 5 20 400 495 8,1 (± 5 %)
PC-C Cyan 500 ± 5 27 440 560 7,3 (± 5 %)
PC-G Green 530 ± 5 30 465 595 6,8 (± 5 %)
PC-A
Amber 590 ± 5 15 555 620 6,2 (± 5 %)
PC-R Red 630 ± 5 15 595 655 5,8 (± 5 %)
NOTE 1 For more information about the definition of UV- and VIS-range see reference [7].
NOTE 2 The above mentioned irradiance values are named as guidelines for the level of irradiance. As well as the
unification to use the same photon flux is a suggestion in order to have a valid basis on the same concentration of
photogenerated active species with respect to the typical heterogeneous catalytic reactions standing behind
photocatalytic reactions. If special photocatalytic measurements need to use different parameters, it is important that
2
these deviations be named and refer to this Technical Specification. The basis of 10 W/m UVA-radiation is a
compromise of outside day and night irradiance during the whole year in Central Europe and therefore also a
compromise between Northern Europe, e.g. Scandinavia, which usually has less irradiance, and Southern Europe, e.g.
Mediterranean Area, which usually has more irradiance. This is the same assumption as to have a compromise between
indoor (most of the time lower) and outdoor (most of the time higher) irradiation conditions.
a
A min. 75 % of the irradiance has to be within FWHM and a min. 93 % of the irradiance has to be within Cut-on- and
Cut-off-Limit. The used irradiance values should represent the same flux of photons within the described part of the
spectra.
Presently only PC-U, PC-V, PC-B, PC-C and PC-G are important for photocatalytic applications. PC-A and
PC-R are only important for future innovations in photocatalytic materials, which use these defined
wavelengths for photo-oxidation processes. Examples of available and suitable filters and LEDs which fulfil
these conditions are shown in A.3 and A.4.
4 Lamp types and filters
4.1 Examples of different lamp types
4.1.1 Xenon lamps
In a pure xenon lamp, the light generation volume is cone-shaped, and the luminous intensity falls off
exponentially moving from cathode to anode. Electrons passing through the plasma cloud strike the anode,
causing it to heat. Pure xenon short-arc lamps have a "near daylight" spectrum, that is, the light output of the
lamp is relatively flat over the entire colour spectrum. All xenon short-arc lamps generate significant amounts
of ultraviolet radiation while in operation. Xenon has strong spectral lines in the UV bands, and these readily
pass through the fused quartz lamp envelope. Unlike the borosilicate glass used in standard lamps, fused
quartz does not attenuate UV radiation. The UV radiation released by a short-arc lamp can cause a secondary
problem of ozone generation. Equipment that uses short-arc lamps as the light source shall contain UV
radiation and prevent ozone build-up. Many lamps have a low-UV blocking coating on the envelope and are
sold as "Ozone Free" lamps. Some lamps have envelopes made out of ultra-pure synthetic, which roughly
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doubles the cost, but which allows them to emit useful light into the so-called vacuum UV region. These lamps
are normally operated in a pure nitrogen atmosphere.
2
NOTE Xe-Arc-bow lamps show the disadvantage when broader areas than 100*100 mm have to be irradiated
homogeneously.
4.1.2 Halogen lamps
A halogen lamp, also known as a tungsten halogen lamp, is an incandescent lamp with a tungsten filament
contained within an inert gas and a small amount of a halogen such as iodine or bromine. The combination of
the halogen gas and the tungsten filament produces a chemical reaction known as a halogen cycle which
increases the lifetime of the filament and prevents darkening of the bulb by redepositing tungsten from the
inside of the bulb back onto the filament. Because of this, a halogen lamp can be operated at a higher
temperature than a standard gas-filled lamp of similar power and operating life. The higher operating
temperature results in light of a higher colour temperature (blue shift). Because of their smaller size, halogen
lamps can be used advantageously with optical systems that are more efficient in how they cast emitted light.
Like all incandescent light bulbs, a halogen lamp produces a continuous spectrum of light, from near
ultraviolet to deep into the infrared.
4.1.3 Fluorescence lamps
A fluorescent lamp or fluorescent tube is a gas-discharge lamp that uses electricity to excite mercury vapour.
The excited mercury atoms produce short-wave ultraviolet radiation that then causes a phosphor to
fluorescence, producing visible light. A fluorescent lamp converts electrical power into useful light more
efficiently than an incandescent lamp. Lower energy cost typically offsets the higher initial cost of the lamp.
The lamp fixture is more costly because it requires a ballast to regulate the current through the lamp. While
larger fluorescent lamps have been mostly used in commercial or institutional buildings, the compact
fluorescent lamp is now available in the same popular sizes as incandescent and is used as an energy-saving
alternative in homes.
NOTE 1 The United States Environmental Protection Agency classifies fluorescent lamps as hazardous waste, and
recommends that they be segregated from general waste for recycling or safe disposal.
Fluorescence lamps have very different spectral distributions, but typically a combination of three or five
different phosphors lead to a three- or five-band fluorescent lamp. Each phosphor used gives characteristic
emission spectra. Comparable peak wavelengths of the phosphors might also shift during the period of use
due to ageing effects (red shift). Some examples for different emission spectra of fluorescence tubes are
given in A.6.
NOTE 2 Due to the different emission bands of various fluorescence tubes, a comparison of photocatalytic activities
will be very difficult.
4.1.4 Mercury vapour lamps
A mercury vapour lamp is a gas discharge lamp that uses mercury in an excited state to produce light. The arc
discharge is generally confined to a small fused quartz arc tube mounted within a larger borosilicate glass
bulb. The outer bulb may be clear or coated with a phosphor; in either case, the outer bulb provides thermal
insulation, protection from ultraviolet radiation, and a convenient mounting for the fused quartz arc tube.
Mercury vapour lamps (and their relatives) are often used because they are relatively efficient. Phosphor
coated bulbs offer better colour rendition than either high- or low-pressure sodium vapour lamps. Mercury
vapour lamps also offer a very long lifetime, as well as intense lighting for several special purpose
applications.
NOTE Hg-low-pressure lamps are only usable for PC-UC.
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4.1.5 Light emitting diodes (LED)
A light-emitting diode is a semiconductor light source. LEDs are used as indicator lamps in many devices and
are increasingly used for other lighting. When a light-emitting diode is switched on, electrons are able to
recombine with electron holes within the device, releasing energy in the form of photons. This effect is called
electroluminescence and the colour of the light (corresponding to the energy of the photon) is determined by
2
the energy gap of the semiconductor. A LED is often small in area (less than 1 mm ), and integrated optical
components may be used to shape its radiation pattern. LEDs present many advantages over incandescent
light sources including lower energy consumption, longer lifetime, improved robustness, smaller size, faster
switching, and greater durability and reliability. LEDs powerful enough for room lighting are relatively
expensive and require more precise current and heat management than compact fluorescent lamp sources of
comparable output.
NOTE Light emitting diodes are available in all spectral ranges defined in Clause 3.
4.1.6 Sunlight
Sunlight, in the broad sense, is the total frequency spectrum of electromagnetic radiation emitted from sun. On
earth, sunlight is filtered through the earth's atmosphere, and solar radiation is obvious as daylight when the
sun is above the horizon. When the direct solar radiation is not blocked by clouds, it is experienced as
sunshine, a combination of bright light and radiant heat. When it is blocked by the clouds or reflects off other
objects, it is experienced as diffused light. The World Meteorological Organization uses the term "sunshine
duration" to mean the cumulative time during which an area receives direct irradiance from the sun of at least
2
120 W/m . Sunlight may be recorded using a sunshine recorder, pyranometer or pyrheliometer. Bright sunlight
2 2
provides irradiance of approximately 700 W/m to 900 W/m at the earth's surface. Sunlight is a key factor in
photosynthesis, a process vital for life on earth.
NOTE Sunlight is not applicable for testing due to fluctuations in intensity, weathering and changes of angle of
incidence.
4.2 Controlling of the ageing behaviour of the used lamp
Lamps have to be checked every 500 h of operation regarding the spectral distribution and the output power
(see also irradiance level in Table 1). If there is a shift, e.g. for fluorescence tubes, of more than 10 nm, lamps
have to be replaced by new ones. If there is a loss in output power, lamps also have to be replaced by new
ones or if it is possible the output power has to be adjusted by changing the distance between the lamp and
the sample.
4.3 Filters
4.3.1 Cut-on/Cut-off-filters for irradiation of large areas
A long-pass-filter (cut-on-filter) is a coloured glass or a plastic foil filter that attenuates shorter wavelengths
and transmits (passes) longer wavelengths over the active range of the target spectrum (ultraviolet, visible, or
infrared). In contrast, a short-pass-filter (cut-off-filter) blocks longer wavelengths and transmits shorter
wavelengths. Long-pass-filters and short-pass-filters, which can have a very sharp slope (referred to as edge
filters), are described by the cut-on respectively cut-off wavelength at 50 % of peak transmission.
4.3.2 Band-pass-filters for irradiation of small areas
A band-pass-filter is mainly an interference filter which works to mask out frequencies that are too low or too
high, giving easy passage only to frequencies within a certain range. The largest available commercial
2
dimensions for band-pass-filters are limited to (50 × 50) mm . Dimensions for customers' specifications are
very expensive in manufacturing. Therefore, a combination of a long-pass- and a short-pass-filter could
simulate a band-pass-filter with respect to the possibility of irradiating larger areas.
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4.3.3 Interference filters
Interference is a characteristic of the wave nature of electromagnetic radiation. Two or more coherent wave
trains of the same wavelength and polarisation state that are superimposed enhance or compensate each
other, depending on the phase relationship and amplitudes of the electric field strength. These filters utilize the
interference effect to transmit or reflect certain spectral ranges of the electromagnetic radiation. Hereto
numerous thin layers with differing refractive indices are applied to a substrate. The optical thicknesses of
these layers are usually a quarter of a given design wavelength or multiples thereof. When electromagnetic
radiation encounters such a multilayer system, the incident beam is split at every interface between two layers
of differing refractive indices into a transmitted and a reflected beam. This process is repeated at every
successive interface, resulting in the formation of numerous superimposing secondary beams that give rise to
interference, either in a constructive or a destructive manner. A wide variety of spectral characteristics with
high transmission or high reflection ratings can be produced by varying the nature, number, thicknesses and
order of the layers. The coatings of the interference filters are manufactured by the process of vapour
deposition under high vacuum. In the case of so-called "soft” coatings, additional measures are normally
taken to protect the filters from damage e.g. by handling or from moisture. This is usually achieved by
supplementary cementing with suitable glass. The upper temperature limit for these filters is essentially
determined by the nature of the optical cement used. Within certain areas of the UV spectrum, it is not
possible to use optical cements due to the inherent absorption involved. In such cases, the coated substrates
are fitted into appropriate mounts and protected by suitable glasses. In the case of so-called "hard” coatings,
the layers of which normally consist of very stable metal oxides, there is generally no need for additional
protection. Depending on the substrate selected, interference filters with hard coatings can be operated at
temperatures up to approximately 350 °C.
5 Diffusers
Commonly used diffuser technologies include prismatic glass integrating bars, ground glass, opal glass,
holographic diffusers and diffractive diffusers. Prismatic glass integrating bars, though sometimes used in high
end systems, are limited in capability, are expensive, and occupy a great deal of precious space. Ground and
opal glass scatter light equally in all directions but offer limited light-control capabilities. In addition, efficiency
is often very poor with these simple diffusers. A holographic diffuser is a step ahead of these diffusers and
enables the production of simple light distribution patterns. Holographic diffusers, however, have limited
control over the light distribution pattern. In general, only round or elliptical patterns can be produced and only
with non-uniform intensity variation, typically of a Gaussian nature. In terms of general beam shaping
capability, diffractive elements can shape an input beam arbitrarily. These are mostly limited to
monochromatic applications with coherent light sources. Diffractive elements are also limited to narrow
diffusion angles due to fabrication limitations, can be strongly sensitive to input beam variations, and present
the well-known problem of zero order, a bright spot co-linear with the incident beam. In many applications, the
zero order is unacceptable and the requirement of single wavelength operation is very restricting. Diffusers
are found in many applications where a bright light source is used to create uniform irradiation over a broad
area. Applications include outdoor lighting, rear projection televisions, and consumer electronic displays.
Traditional ground or opal glass diffusers are inefficient and have limited capabilities when it comes to
controlling the shape of the irradiated area. More modern holographic diffusers can typically be made so that
round or elliptical areas are irradiated but the intensity of
...
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