Contents

1. GENERAL

2. PROGRESS

3. CONTRIBUTION OF THE PARTICIPANTS

4. ANNUAL REPORTS OF THE WORKING GROUPS

4.1 Working Group 1

4.2 Working Group 2

4.3 Working Group 3

4.4 Working Group 4

5. MILESTONES

Annex1: Contribution of the participants

1. GENERAL

The Thematic Network for Ultraviolet Measurements started its operation on 15^th of November 1997. This is the first annual report of the Network, describing its progress during period 15/11/1997­14/11/1998.

2. PROGRESS

2.1 First Workshop

The Network arranged its first workshop in Espoo, Finland, on March 2 and 3, 1998. Participation to this workshop was restricted to members of the Network only. The number of participants was 69. More information on the progress of the 1^st workshop may be found in the first report of the Network (May 1998).

2.2 Second Workshop

The Network arranged its second workshop in Braunschweig, Germany, on November 9-11, 1998. The second workshop was not restricted to the members of the Network, as the first workshop was. The number of participants therefore increased to 88. Many of the participants were from other than the participating organisations, which expands the Network significantly. It should be noted that some participants came from China, Czech Republic, Poland and United States, which indicates that the Network has also generated interest outside the European Union. There were also new participants from France.

Major part of the meeting time was allocated to parallel sessions of the Working Groups, and to presentations of the Working Group leaders on their progress. Progress reports of the Working Groups may be found starting from page 5 in this report.

More information on the progress of the 2^nd workshop, including the lists of participants and presentations, may be found in the minutes of the workshop (March 1999).

2.3 WWW-Pages

The WWW-pages of the Network have been opened and announced public in March, 1999. The pages may be found in the address: http://metrology.hut.fi/uvnet/. The following items have been included in the pages so far:

1. General information about the Network and the Working Groups,
2. Contact information for the participants and WG members, including postal and E-mail addresses, and links to WWW-pages,
3. Mailing lists for the Working Groups and participants,
4. Reports and Newsletters published so far,
5. Minutes of meetings and workshops,
6. News and forthcoming events like workshops.

Improvement of the pages will continue in 1999.

2.4 Newsletter

The first Newsletter (UVNEWS) of the Network was issued in September 1998. The first UVNEWS included reports and extended abstracts of the first workshop and announced the second workshop. The news section of UVNEWS appeared to be quite popular. Many organisations used it to promote their progress in the field of UV measurements.

2.5 Training Courses

The dates and location of the first training course have been fixed. The training course will be arranged at NPL in Teddington, on September 6-8, 1999. This is somewhat later than originally planned. The reason for the delay is that the training course will be combined with the third workshop (Teddington, September 8-10, 1999) of the Network. This will reduce the travel costs of the lecturers, who are mainly participants of the Network.

The date and location for the second training course have not been fixed yet, but it is very likely that this training course will be arranged in south-eastern part of Germany or in Austria.

2.6 Financial Status

According to the first cost statement, the Network has used 124 816,71 ECU of the allocated 379 930 ECU.

Some participants have not been able to attend both workshops, which has resulted in financial savings. 20 organisations have not attended a workshop in a foreign country, and 2 organisations did not attend a domestic workshop, which result in saving of 17 400 ECU. Some organisations have not spent the maximum amounts of money reserved for travelling to each workshop, but as agreed with the Commission, these participants may use these savings to cover their higher expenses of some other workshops. They may also use these savings to cover 20 % overheads.

It is proposed that the 17 400-ECU savings will be allocated as follows:

1. Arranging the workshops has appeared to cause much more work for the local organisers than was originally planned. PTB, NPL and SP would therefore each get an additional 1 500 ECU to compensate for their extra work.
2. The second training course in year 2 000 will be arranged in Germany or Austria, instead of Teddington, to attract more attendants from central and southern Europe. The local organiser would get 2 000 ECU to cover their extra work.
3. The circulation of UVNEWS has increased rapidly. The 150 issues of the first newsletter ran out in a matter of weeks. It is therefore proposed that an additional 4  300 ECU would be allocated to printing costs of UVNEWS.
4. The remaining 9 700 ECU would be used for inviting guests to the workshops. These guests will include e.g. co-ordinators of relevant UV projects, specialists in an important UV field, organisations in countries which have one ore no participants at all in the Network, and industrial organisations.

The proposed changes do not exceed the original budget. The savings of the remaining workshops will be allocated separately after consulting the Commission.

2.7 New Participants and Invited Guests

University of Oslo has withdrawn from the project. As a replacement, Laboratoire National d'Essais (LNE, France) has been appointed as a regular participant in the Network. LNE has participated in both the first and the second workshop and works actively in Working Group 4.

Some financial savings have been used to invite guest lecturers in the workshops. Guests invited so far are:

1. UMIST Ventures Ltd, UK (Dr. Ann R. Webb).
2. Ingenieurbüro iSiTEC Hanken & Hoops GbR, Germany (Thomas Hanken).
3. NPL Management Ltd, UK (Dr. Neil Harrison) Co-ordinator of SMT4-CT98-2242: Improving the accuracy of ultraviolet radiation measurements.
4. Physikalisch-Technische Bundesanstalt, Berlin, Germany (Dr. Hans Rabus) Co-ordinator of EUROMET 437: Evaluation of the radiometric performance of UV photodetectors.
5. DLR Institut für Luft- und Raumfahrtmedizin, Germany (Dr. Petra Rettberg) Representing the co-ordinator of ENV4-CT95-0044: BIODOS, a project to develop biological dosimetry systems for monitoring the impact of environmental UV radiation on human health and the biosphere.

3. CONTRIBUTION OF THE PARTICIPANTS

The contribution of the participants in the operation of the Network has been given in Annex 1. In addition:

1. Helsinki University of Technology has co-ordinated the Network activities, arranged a workshop in Helsinki, edited the first UVNEWS, implemented the WWW-pages, and is a member of the steering group.
2. Physikalisch-Technische Bundesanstalt has arranged a workshop in Braunschweig, and is a member of the steering group.
3. Gigahertz-Optik Vertriebsgesellschaft für Technische Optik mbH is a member of the steering group.
4. NPL Management LTD has been planning the training courses and is a member of the steering group.
5. University of Dundee is a member of the steering group.

The steering group was set at the first workshop to make decisions on practical matters of the Network.

4. ANNUAL REPORTS OF THE WORKING GROUPS

4.1 Working Group 1: Guidance for UV Power Meter Classification for Particular Applications

This Group will concentrate on making an international proposal for characterisation of UV-meters.

4.1.1 Aim

To produce a proposal which could be accepted, or parts of it, by other committees which are working on similar regulations.

4.1.2 State of the art

There is no general accepted regulation for characterising UV-meters in the world.

To achieve its aim, WG1 has been working on getting information from the other working groups in the world, which are also working on drafts for this topic.

We are in contact with:

1. Berufsgenossenschaft Fachausschuss Elektrotechnik "Incoherent optical radiation,"
2. CIE TC 2-47 " Characterisation and calibration methods of UV radiometers,"
3. CIE TC 6-45 "Workplace safety,"
4. DIN FNL 7.5 "Radiometer for measurement of actinic radiation quantities,"
5. MOHR "International Symposium and Workshop on Measurement of Optical Radiation Hazards," and
6. WMO-SAG "Instruments to measure solar ultraviolet radiation."

We want to find a consensus view on the above ideas and to make our own proposal for industrial UV-radiometry.

4.1.3 Actions taken

All members were informed about the aims and the regulations to get easy and effective communications. The first proposals on how to classify UV-meters were made. The members gave feedback via E-mail and phone. The group contacted other working groups in the world via E-mail and phone mentioned above and got also invitations to visit some of the groups. We were able to be active at the group "Berufsgenossenschaft Fachausschuss Elektrotechnik" with the theme "Inherent optical radiation." After making the 1^st draft of the document, all members got the information. With the feedback of this, the 1^st revised draft was made.

4.1.4 Progress

Revised 1^st Draft of the document "Characterising the performance of integral measuring UV-meters" was released on 27.10.98 (see attachment).

4.1.5 Plans for the future work

We plan to take part in the "DIN FNL 7.5" group with the theme "Radiometer for measurement of actinic radiation quantities" and continue with the "Berufsgenossenschaft Fachausschuss Elektrotechnik." Also, we will be looking for the papers given from the other groups mentioned above. We will rework the paper again with the new information from the other groups.

In the final paper, the following items should be included:

1. definitions of the possible uncertainties of the detector head and read out meter,
2. classifications of the UV-meters depending on the uncertainties,
3. calibration methods, and
4. measurement methods for the user for getting less additional uncertainties.

With this proposal, either the manufacturer of UV-meters or the user of them should be able to classify their UV-meters. This means that the manufacturer will get information on how to characterise the meters with detector-heads and how to calibrate them. The user will get information on how to do good measurements with less addition of uncertainties.

During our work, we have found that it will be necessary to look also at the spectral UV-measurements, because these measurements are the basis for the integral reachable uncertainties. Also, we have found that for measurements weighted with action spectra, the UV-range has to be extended.

Reported by Anton Gugg-Helminger, February 12, 1999.

4.2 Working Group 2: Improvement of Measurement and Calibration Methods for Spectrally Resolved UV Measurements

4.2.1 Objectives

The objectives of WG 2 are:

1. To determine the user requirements for spectrally resolved calibrations of standards and characterisations of instruments and components in the field of non-coherent UV radiometry and spectrophotometry;
2. To stimulate and promote the improvement and development of measurement techniques and exchange of experiences based on the respective needs and problems as well as on the state-of-the-art methods, devices and instruments identified by WG 2 before;
3. To prepare and publish a report with examples of the expression of the uncertainty of measurement in UV radiometric calibrations based on the documents EAL-R2 and EAL-R2-S1 and in compliance with the recommendation of the ISO Guide to the Expression of Uncertainty in Measurement. The goal is to demonstrate the method of evaluating the uncertainty of measurement in spectroradiometry, to support the reduction of the too large uncertainties in UV radiometry and to facilitate the evaluation of realistic reported uncertainties.

4.2.2 Background

Based on the discussion during the first meeting and based on the feedback on a first questionnaire, WG2 will cover the following areas in the field of non-coherent UV radiometry and spectrophotometry:

Calibration of detectors, spectroradiometers, sources (lamps), reflection standards and filters; characterisation/testing of detectors, sources, optical instruments, components, materials and surfaces.

UV dosimetry (irradiance more than 10 mW cm^-2) will be treated by WG3, and although UV laser radiometry is of increasing importance (e. g., in photolithography), this field will be excluded because only one WG2 member seems to be involved.

In the classification of measurement and calibration methods including QA/QC requirements, the following categories are distinguished: absolute calibrations requiring traceability to SI units and national standards as well as recognition of the equivalence of the standards for the respective units and scales (e. g., calibration of a lamp as a UV standard of spectral irradiance); characterisation and testing based on relative measurements (e. g., measurements of the angular response of a diffuser to determine cosine error).

4.2.3 Actions taken

WG 2 with 33 members was formed during the first workshop in Espoo (March 1998), meanwhile with more than 60 members including guests after the first WG 2 meeting.

A first questionnaire has been sent to the members of WG 2 in order to determine the state of the art and needs in the field of spectrally resolved UV measurements and, moreover, to find out the work areas covered by the members of WG 2 (see section 4.2.2). About 25% of the participants replied.

The first WG 2 meeting during the second workshop in Braunschweig (November 1998) focused on scope and delimitation of WG 2 work, the discussion of the feedback on the first questionnaire and the identification of measurement problems. Special attention was paid to the evaluation of uncertainties including QA/QC requirements. Uncertainty evaluation in the case of spectrally resolved UV measurements including interpolation of data is a pressing problem which will require much more attention and work in the future.

Three speakers were invited for presentations during the second workshop to exemplarily cover different areas of the field of WG 2. Thus, the following talks were given:

1. Rabus (PTB, Berlin): Evaluation of the Radiometric Performance of UV Photodetectors;
2. Jordan (Osram GmbH, München): UV Measurements at an Industrial Calibration and Measurement Laboratory;
3. Webb (UMIST, Manchester): Uncertainty Estimate for the Spectral Measurement of Solar UV Radiation.

4.2.4 Progress

First of all, the scope of WG 2 work has been defined (see section 4.2.2) and our objectives established. Some of the needs and problems already identified are as follows, where several members reported on activities to overcome the respective difficulties: discrepancies between standards of UV spectral irradiance from different National Metrology Institutes (NMIs); stability of UV radiometric standards (lamps and detectors); calibration of UV spectroradiometers for field measurements including transfer from horizontal to vertical optical axis; total (4) UV spectral radiant power measurements for an overall lamp characterisation; measurement of the transmittance of UV filters. Up to now, there is more feedback from institutes involved in the monitoring of UV solar radiation than from industry and calibration laboratories.

Uncertainty evaluation has been started with a draft for the calibration of a standard of spectral irradiance describing measurement problem, mathematical model and sources of uncertainty of measurement. Furthermore, the uncertainty evaluation of interpolated spectral data is an important subject under discussion, where the first proposal was mainly an introduction to this problem.

In the field of UV monitoring, WG2 refers to the QC/QA activities of the WMO [A. R. Webb et al., Guidelines for Site Quality Control of UV Monitoring, WMO/GAW Report No. 126, 1998] gathering information on additional and specific uncertainty sources of UV spectroradiometers for field measurements.

4.2.5 Plans for the future work

The next WG 2 meeting will take place during the third workshop in Teddington (September 1999).

Future work including the preparation of the next meeting is based on the feedback on more questionnaires and on drafts for the preparation of the report on uncertainty evaluation. According to the first objective in section 4.2.1, the second questionnaire has already been sent to all members and guests in December 1998. In order to motivate as many members as possible to reply, this questionnaire is reduced to provide information only about the problems and requirements in the case of spectrally resolved UV measurements. Based on these results, questionnaires and e-mail messages will be used to succeed in our second objective (see section 4.2.1).

Examples of uncertainty evaluation according to the third objective will be prepared separately. Drafts will be sent by e-mail asking for corrections, comments as well additional and alternative points or sections:

1. Uncertainty evaluation will be started with a draft for the calibration of a standard lamp of spectral irradiance.
2. As one area of the EU project "Improving the accuracy of UV radiation measurements" is the establishment and comparison of UV spectral responsivity scales based on cryogenic radiometers achieving a reduced uncertainty, an important joint goal is also the respective uncertainty evaluation of detector calibration.
3. Finally, the uncertainty evaluation of interpolated spectral data is indispensable to spectrally resolved measurements, where the proposal during the first meeting will be the basis for a separate draft.

Reported by Jürgen Metzdorf, February 17, 1999.

4.3 Working Group 3: Improvement of Measurement and Calibration Methods for Spectrally Weighted UV Measurements

4.3.1 Objectives

The objectives of this Working Group are:

1. to define the user requirements for calibration,
2. to determine the current best practise, and
3. to develop/recommend best techniques for the calibration of spectrally weighted UV measurements as a function of accuracy/application.

This will culminate in the production of a document which will help those making measurements or suppliers of equipment to identify sources of uncertainty relevant to their application and an appropriate method to assess its level

4.3.2 Background

The aim of this working group is to draw together problems and requirements from a range of technical areas and hopefully bring together solutions/ best-measurement practise from one technical area into another. It is clear that at the start of this exercise, interaction between groups is relatively poor. It is also true that some technical disciplines are more advanced than others (notably solar UV monitoring), but also that the demands of some are not as critical.

The main aim at the start of the project is to get together a pool of information as to what is known and what is perceived to be known with the aim of linking it together in a document which then provides readers with links to the current state-of-the-art in terms of measurement/characterisation for their particular measurement application. However, an important goal in this is to ensure that the selected solution is only at a level required by the application and does make the application economically non-viable.

4.3.3 Actions taken

The group has so far carried out its activities through a process of questionnaires and discussion at a meeting of the second workshop. This process has sought to identify:

1. the types of measurement carried out which require a spectrally weighted function,
2. the uncertainty requirements for the application,
3. uncertainties achieved both specified by manufacturers and believed by users, and
4. possible sources of uncertainty.

4.3.4 Progress

A significant baseline of knowledge has been procured as to the underpinning requirements, although there are still some gaps in the knowledge base, particularly for dosimetry applications, although efforts are being made to identify inputs to this. It is expected that during the next year, a draft document will be produced which will identify all potential sources of error and review potential calibration/characterisation methods. This document will also seek to develop a structure to allow the reader to identify their type of application and from that assess the error sources likely to contribute, and their relative size so that a decision can be made as to which type of instrument should be used for which application and which sources of error need to be investigated in detail.

4.3.5 Plans for the future work

Ultimately, it is intended that the document in its final form will be published and be available widely probably linked or incorporated in the document being developed through WG1. Similarly, the document is likely to involve inputs from WG4. During the next period a first draft is intended to be produced.

Reported by Nigel Fox, March 2, 1999.

4.4 Working Group 4: UV Measurements Related to Health and Safety

4.4.1 Aim

The aim is to provide practical advice on suitable measurement techniques in health and safety aspects of ultra-violet radiation.

4.4.2 Background

There are known hazards caused by exposure to UV radiation. Also, its use in medicine is potentially beneficial. Recently, there have been widespread concerns over the safety of sunbeds and also uncertainty on appropriate measurement techniques.

4.4.3 Actions taken

The working group was formulated at the first meeting of the network in Espoo, Finland 2-3 March 1998 and subsequently met in Braunschweig Germany 9-11 November 1998. In addition, considerable communication has taken place by E-mail. The group decided to concentrate initially on sunbeds and to produce an agreed methodology appropriate for measuring UV from an artificial tanning unit.

4.4.4 Progress

It has been established that the relevant standard throughout the EC is EN 60335-2-27 (March 1997) although other complementary or normative standards or guidelines also exist. At present, there are areas where there is a difference of interpretation. These include site of measurement, use of mean or maximum values. Equivalency of replacement lamps is another difficulty. WG4 is identifying these areas. It was noted that Finland, France, Norway and Sweden had regulations covering UV emissions from sunbeds.

It has become apparent that there is a need for a common approach to how measurements are carried out.

Health risks were identified as follows: skin cancer, reduced immunlogical status, skin ageing, erythema, keratitis, cataract. Benefits were: cosmetic, psychological, vitaminD. The opinion of the group was that the risks greatly outweigh the benefits. There is a need for public information.

Training needs for operators were considered. This should include advice on replacement lamps and filters.

4.4.5 Plans for the future work

The working group will seek to produce a consensus view on interpretation of the European standard for sunbed testing.

The working group will seek to produce a recommendation on how measurements should be carried out on artificial tanning units. This will include establishing a database of existing published studies and guidelines, describing necessary measurement tasks, and specifying performance requirements for suitable measuring devices.

The need for public information will be considered further.

Training needs for operators will be considered further.

Reported by Harry Moseley, February 12, 1999.

5. MILESTONES

Signed in Espoo, March 5, 1999
Erkki Ikonen
Coordinator of the Network

Annex 1: Contribution of the participants to the operation of the Network

Legends: WS1 and WS2 - Number of persons attending the workshops; WG1-WG4 - Number of persons in the Working Groups; NCP - Organisation has acted as a contact person in the given country; WG Leader - Organisation has acted as a Working Group leader in the given Working Group.