teco2005wrc/pmod quality management1 the world radiometric reference and its quality system iso/iec...

TECO2005 WRC/PMOD Quality Management 1

The World Radiometric Reference and its Quality System ISO/IEC 17025

Wolfgang Finsterle, Isabelle Rüedi, and Silvio Koller

Introduction

PMOD/WRCTasksIPCMetrology

Quality System

OrganizationResponsibilitiesManagement ReqirementsTechnical RequirementsComparison WRR/SIOutlook


World Radiation Center

The World Radiation Center (WRC) is operated by the Physikalisch-Meteorologisches Observatorium Davos (PMOD) on assignement by WMO. The WRC is financed by the Swiss governement.

Introduction


Quality System



WMO Mandate to WRC

To maintain the World Standard Group (WSG) for the realization of the World Radiometric Reference (WRR)Note: The WRR has been defined in 1980 based on the mean value of 15 absolutely characterized cavity radiometers. The WRR is the primary standard for solar irradiance.

Today the WRR is realized by the WSG, a group of currently six reference pyrheliometers permanently installed at PMOD/WRC.

To ensure at all times the highest possible quality of its standards and testing equipment

To serve as calibration center for regional radiation centers worldwide

Introduction


Quality System



Calibration Tasks

Calibration of:

Pyrheliometers Pyranometers

with the Sun as source

Introduction


Quality System


WSG candidates

World Standard World Standard GroupGroup


IPC - International Pyrheliometer Comparison This key event is

held every 5 years since 1959

The goals are:- to ensure the homogeneity of solar irradiance measurements worldwide- to monitor WRR stability

Participating instruments are compared to the mean value of WSG instruments

validation of WRR stability based on IPC results

Introduction


Quality System


IPC-IX IPC-IX 20002000


WMO, BIPM, and the WRR

WMO and the Bureau International des Poids et Mesures (BIPM) co-operate to ensure that meteorological data are traceable to SI units

The quantity ‘Solar Irradiance’ was proposed to the Consultative Committee on Photometry and Radiometry (CCPR)

The ‘connection’ between the WRR (W/m2) and SI units needs to be validated

Introduction


Quality System



The Need for a Quality System

The WRR was originally defined in 1980 as the average of 15 absolutely characterized cavity radiometers

Since then it has served the meteorologial community as the primary standard for solar irradiance

Several ISO standards now require traceability to the WRR

The WRR is no longer only a meteorological standard but accepted in a much wider metrological community

Introduction


Quality System



Why ISO/IEC 17025?

International recognition in the formal framework of the CIPM Mutual Recognition Arrangement (MRA) requires a Quality System (QS) according to the international standard ISO/IEC 17025. Conformance with ISO/IEC 17025 is also more and more requested by calibration customers.

The QS at PMOD/WRC was introduced in December 2004 and presented to EUROMET QS-Forum 12 in February 2005.Major goal of the quality system:

To maintain the WSG and thus the WRR with the highest possible stability and to provide the highest possible world-wide homogeneity for solar irradiance measurements.

Introduction


Quality System



PMOD / WRC Quality ManagementQuality Manger

DepartmentAbsolute and Shortwave Radiometry

Head of Department

DepartmentInfrared

Radiometry

Not yet integrated

DepartmentWORCC

Not yet integrated

QS Organization

At this time the Quality System at PMOD/WRC covers only the department of ‘Absolute and Shortwave Radiometry’. It is planned to be extended in the future to cover all departments at PMOD/WRC.

Introduction


Quality System



QS Responsibilities

Transfer and implementation of top level QS into department

Full responsibility for department specific QS issues

WSG and data evaluation

Head of Department

Execution and records of calibration tasksLaboratory Assistant

Top level QS tasks Improvement and adaptation of the quality

management handbook and associated documentation

Quality Manager

Introduction


Quality System



Management Requirements

1. Document Control2. Contracts3. Changes / Complaints / Non-conformities4. Audits / Management Reviews

The goal was to introduce already used, well-established processes into QS and to adapt them only where necessary

1 and 2 were basically existing, 3 and 4 had to be defined and implemented

Short experience time=> usefulness and user friendliness still have to be proven

Introduction


Quality System


ISO/IEC 17025 requires standard procedures, mechanisms, and plans to be followed for


QS Technical Requirements

Calibration / Validation Data evaluation procedures and

timing definitions for every instrument type need to be documented– Pyrheliometers: based on ISO

9059– Pyranometers: based on ISO

9846 Differences to standards are

stated in QS documentation Techniques:

– Use of reference standards (voltmeters)

– Indirect comparison WSG <> cryogenic radiometer

– Assessment of uncertainties

Introduction


Quality System



QS Technical RequirementsEnvironmental Conditions– Clear sky– Continuous weather watch during the calibration– Standard room temperature at data acquisition unit– Prohibited use of cell phones near DAQ hardware

ISO/IEC 17025 requires Traceability to SI units, but: WRR is a primary reference WRR is the only primary reference for solar irradiance

in the world (no key comparisons possible) To-date cryogen radiometers cannot measure solar

irradiance only indirect power comparisons are possible

Power comparisons to national cryogen standards

Reference voltmeter calibration at certified laboratory

Introduction


Quality System



QS Technical Requirements

Individual estimates of uncertainties for each WSG member instrument were calculated

Original estimate of absolute uncertainty for the WRR relative to SI units is +/- 0.3%

Relative uncertainty WRR transfer < 300 ppm(Confirmed by IPC 1985 – 2000 results)

Individual estimates of uncertainties for different calibration items (instrument types) were calculated

Introduction


Quality System


ISO/IEC 17025 requires detailed estimates of the uncertainties


Comparison WRR/SI

0.999600

0.999800

1.000000

1.000200

1.000400

1.000600

1.000800

1.001000

1.001200

0 20 40 60 80 100

data sample

WRR/SI

Results from recent intercomparisons between the WRR and cryogenic standards at METAS (Bern) and NPL

(London)

Introduction


Quality System


by Sandra Moebus

metas NPL


Outlook

Implement requests from EUROMET QS-Forum 12

1st review of PMOD/WRC QS

Challenging tasks:– Enlargement of parallel data

acquisition capability (2-3 years)

– DAQ S/W development forIPC 2010

– Integration of the remaining two PMOD departments(Infrared and WORCC)

Introduction


Quality System



Thank you! Any questions?

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teco2005wrc/pmod quality management1 the world radiometric reference and its quality system iso/iec...

Documents

quality system isoiec

wrr wmo

highest possible quality

world standard group

world radiation center

calibration center

primary standard

quantity solar irradiance