GAZ SAYACI ÖLÇÜMLERİNDE HATA VE BELİRSİZLİK UYGUNLUĞU DEĞERLENDİRMESİ

Öz

Akredite laboratuarların yaygınlaşmaya başlaması sonrasında gaz debi ölçümü alanında kalibrasyon yöntemleri, referans sistemler, ölçümler ve izlenebilirlik gibi konularında ortaya çıkan sorular ve çözüm beklentileri artmaktadır. Bu alanlardaki kalibrasyonların uluslararası düzeyde kabul gören yöntemler ve standartlar doğrultusunda yapılması, gerçekleştirilen karşılaştırmaların sonuçlarının yorumlanması, akreditasyon uygulamalarının etkinliğinin doğru değerlendirilmesi ve hata ve belirsizlik hesaplamaları oldukça önemlidir. Gaz sayacı üretimi ve gaz dağıtımı şirketleri kendi bünyelerinde kurdukları akredite laboratuarlarda gaz sayacı kalibrasyonları, ayar istasyonları ve doğrulama ünitelerinin izlenebilirliğini sağlama çalışmaları yapmaktadır. Referans cihazların kalibrasyonu, izlenebilirliği ve belirsizlik hesaplamaları konularında kalibrasyon firmalarından gelen soruların uluslar arası standartlar ve uygulamalar da yer alan cevapları TÜBİTAK UME Akışkanlar Mekaniği Laboratuarında ki tecrübeler dahilinde bu makalede paylaşılacaktır.

Anahtar Kelimeler

• gaz sayacı
• ölçüm
• kalibrasyon
• hata
• belirsizlik

Conformity Assessment of Error and Uncertainty in Gas Flowmeter Measurements

Öz

The demand for solution to problems related with the calibration methods, reference systems, measurements and traceability issues in gas flow measurement area increased after the accredidated laboratories becoming widespread in country. It is important to realize the calibrations according to methods described by international standards, to comment on intercomparison results, to evaluate the effectiveness of accreditation requriements and to calculate measurement error and uncertainty. Most of the gas meter manufacturers and gas distribution companies have their own adjustment and calibration laboratories for measurement and traceability purposes. The calibration of reference devices, traceability and uncertainty considerations are discussed in this paper with the answers in international standards and laboratory experience at TÜBİTAK UME.

Anahtar Kelimeler

• gas meter
• measurement
• calibration
• error
• uncertainty

Kaynakça

1. 1. BIPM JCGM.106, (2012). Evaluation of measurement data - The role of measurement uncertainty in conformity assessment.
2. 2. BS EN 12261, (2018). Turbine gas meters.
3. 3. BS EN 12405, (2010). Gas Meters - Conversion Devices.
4. 4. BS EN 12480, (2018). Rotary displacement gas meters.
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8. 8. Directive 2014/32/EU, (2014). Directive of the European Parliament and of the Council of 26 February 2014 on the harmonisation of the laws of the Member States relating to the making available on the market of measuring instruments.

9. 9. EA-4/02, (2021). Expression of the uncertainty of measurement in calibration.
10. 10. EN1359/A1, (2006). Gas meters – Diaphragm meters.
11. 11. GUM, (1995). Evaluation of measurement data - Guide to the expression of uncertainty in measurement.
12. 12. ILAC G24, (2007). Guidelines for the determination of calibration intervals of measuring instuments.
13. 13. ILAC G8:09, (2019). Guidelines on Decision Rules and Statements of Conformity.
14. 14. ISO 14253-1, (2017). Geometrical Product Specifications (GPS)-Inspection by measurement of workpieces and measuring instruments-Part1:Decision rules for verifying conformity or nonconformity with specifications.
15. 15. ISO 5168, (2005). Measurement of fluid flow - Procedures for the Evaluation of uncertainties.
16. 16. ISO 9300, (2005). Measurement of gas flow by means of critical flow venturi nozzles.
17. 17. ISO/IEC 17025, (2017). General requriements for the competence, impartiality and consistent operation of laboratories.
18. 18. OIML G19, (2017). The role of measurement uncertainty in conformity assessment decisions in legal metrology.
19. 19. OIML R137 1&2, (2012). Gas meters Part 1: Metrological and technical requirements.
20. 20. PTB Testing Instructions Volume 25, (2003). Gas Meters-Test Rigs With Critical Nozzles, Braunschweigh.