Calibration of Meteorological Instruments and Uncertainty Calculation

The Egyptian Meteorological Authority in Cairo hosted the WMO Training workshop on the Calibration of Meteorological Instruments and Uncertainty Calculation for from 11 to 13 December 2023, followed by a one-day Regional Instrument Centre Consultation Workshop on 14 December. The practical, interactive training events aimed to improve calibration facilities and capabilities in the National Meteorological and Hydrological Services (NMHSs) of WMO Regional Association I (RA I, Africa) towards their obtaining or maintaining ISO/IEC 17025 accreditation.

At the start of the first workshop, each participant – NMHSs staff responsible for calibrations and uncertainty calculation, particularly for temperature – presented the uncertainty budgets and calibration and measurement capabilities (CMC) of their NMHS. The training covered metrology in meteorology, interlaboratory comparisons, competencies of laboratory personnel, terminology and vocabularies, then went on to focus on calibration procedures and the computation of calibration uncertainties for temperature, pressure and humidity as well as for precipitation and wind.

The one-day hybrid Regional Instrument Centre (RIC) Consultation Workshop aimed to strengthen their support to NMHSs in their region and further afield, to improve collaboration between the RICs, and to develop strategies to improve the quality of observations. Almost all of the RICs participated (Algeria, Argentina, Egypt, France, Germany, Japan, Kenya, Morocco, Philippines, Slovakia, Slovenia and Turkey) as well as the China Regional Marine Instrument Centre (RMIC). The RIC try to tailor assistance to each NMHS’s expectations, challenges and specific needs, but these can be quite different even within a region. Though some regions do have well-established national metrology systems, the RICs often face similar challenges when it comes to providing NMHSs with traceability assurance services:

• A lack of awareness in certain regions or NMHSs of the importance of traceability assurance systems
• A lack of awareness of RIC capabilities in certain regions
• Traceability assurance is not prioritized in some NMHSs
• Problems with the transportation of equipment (cost, customs, procedures)
• Lack of resources – staff, equipment, traceability, procedures, etc – in some developing RICs.

Four recommendations, based on regional needs, came out of the consultation:

1. RICs need to promote their functions and capabilities in collaboration with RAs
2. All RICs should obtain ISO/IEC 17025 Accreditation
3. Service laboratories and network maintenance should kept strictly separate – in different units/divisions – to maintain ISO/IEC 17025 RIC Accreditation.
4. Guidance on field verification is strongly needed (including equipment specifications, procedures, tolerances for field verification, etc).

The participants proposed that a dedicated RIC online platform be developed to strengthen cooperation.