Calibration, traceability, uncertainty and comparing measurement results. Workshop 16 March 2015 VSL, Delft The Netherlands

Transcription

1 Calibration, traceability, uncertainty and comparing measurement results Workshop 16 March 2015 VSL, Delft The Netherlands 1

2 Calibration Calibrating an instrument involves comparing the measurements of two instruments; one with a known magnitude or correctness (standard/reference device - REF), against which you measure the device under test (DUT) REF 2

3 Calibration Calibration is required for: Testing a new measurement instrument Testing a measurement instrument after it has been repaired or modified Periodic testing of measurement instruments Testing after the specific usage has elapsed Prior to and/or after a critical measurement When observations are not accurate or instrument indicators do not match the output of a surrogate measurement instrument After events such as: An measurement instrument has had a shock, vibration, or exposure to adverse conditions, which can put it out of calibration or damage it. 3

4 Calibration Risks involved in not calibrating an instrument Safety procedure Wastage Faulty or questionable quality Fines or litigations Increased downtime 4

5 Calibration Calibration frequency Manufacturer-recommended calibration interval. Before a major critical measuring project. After a major critical measuring project. After an event (error, damage, shocks) Per requirements. Monthly, quarterly, or semiannually. Annually. Biannually. Never. 5

6 Metrological Traceability property of a measurement result whereby the result can be related to a reference through a documented unbroken chain of calibrations, each contributing to the measurement uncertainty BIPM Paris Traceability Process industry, Aviation, Meteorology, Pharmacy, Science 6

7 Metrological Traceability 7

8 Metrological Traceability Certificate Primary Pressure Standard 0,003 % National Metrology Institute (NMI) Process Certificate 0,2 % Calibration Validation 0,05 % 0,01 % Certificate Accredited Calibration Laboratory Traceability from Industry to a NMI Certificate

9 Metrological Traceability weights Piston cylinder unit time Pressure medium mass length

10 Metrological Traceability BIPM Paris Grand K (BIPM) 1 kg 0 mg PtIr (NMI) 1 kg 0,010 mg Reference standards (NMI) 1 kg 0,026 mg Working standards (NMI) 1 kg 0,150 mg (E1) Mass standards (Accr. laboratories) 1 kg 0,50 mg (E2) Mass standards/scales (Industry) 1 kg 1,50 mg t/m 500 mg (F1 M3) 10

11 Measurement Uncertainty U = 1 mm U = 0, mm

12 Measurement Uncertainty U = 0,02 bar U = 0,0002 bar

13 Measurement Uncertainty U = 0,1 kg U = 0, kg

14 Measurement Uncertainty U = 1 C U = 0,0001 C

15 Measurement Uncertainty U = 2 L U = 0,0025 L

16 Measurement Uncertainty Type A evaluation Several (in)dependent observations Observable scatter in the values obtained Statistical methods Type B evaluation Calibration of the reference standard Ambient conditions Calibration method Calibration/test engineer 16

17 Measurement Uncertainty 17

18 Measurement Uncertainty 18

19 Measurement Uncertainty 19

20 Interlaboratory Comparisons Competenc e personnel Participation ILC s and PTS Approved Test and Calibration Methods Improvement of Quality Test and Calibration Results 20

21 Interlaboratory Comparisons NMI Regional NORAMET comparison NMI BIPM NMI Global CIPM comparison NMI NMI NMI NMI NMI NMI EA lab RvA lab lab RvA lab National comparison or PTS NMI VSL, Delft NMI lab NMI Regional EURAMET/COOMET/AFRIMET comparison National comparison RvA lab NMI EA lab EA lab EA lab lab Regional EA comparison EA lab 21

22 Lref L001 L002 L003 L004 L005 L006 L007 L008 L009 L010 L011 L012 L013 L014 L015 L016 L017 Deviations Lref - participants /kpa Interlaboratory Comparisons Agreement Lref - participants at kpa g 70,0 60,0 50,0 40,0 30,0 20,0 22

23 Nominal pressure Deviation Uncertainty Deviation Uncertainty Deviation Uncertainty Deviation Uncertainty Deviation Uncertainty Lref L013 L014 L015 L016 Interlaboratory Comparisons Lab Normalized Error E N kpa kpa kpa kpa kpa 0 0 1,3 0,0 0,7 0,00 0,0 3,0 0,00 0,0 3,0 0,00 0,0 0,0 0, ,0-7,0 1,7 1,56-6,5 4,2 0,99-11,0 5,0 0,02-7,7 5,0 0, ,1-4,5 2,7 1,38-6,0 6,3 0,60-13,0 6,0-0,41-6,6 7,2 0, ,0 5,0 3,7 1,16 3,5 8,0 0,54-6,0 6,0-0,65 3,7 9,4 0, ,0 19,5 4,7 0,94 18,0 10,0 0,44 6,0 8,0-0,75 18,4 11,6 0, ,3 35,5 5,7 0,71 35,5 13,0 0,41 22,0 10,0-0,64 35,5 13,7 0, ,6 53,5 6,7 0,60 54,0 15,0 0,39 40,0 11,0-0,56 53,0 15,9 0, ,7 72,0 18,0 0,31 58,0 13,0-0,49 69,9 18,1 0,21 Normalized Error E N Normalized Error E N Normalized Error E N 23

24 ISO/IEC 17025:2005 Key-issues: Competence staff Calibration/testing method Equipment and/or instruments Uncertainty calculation Traceability Ambient condition and facilities Interlaboratory comparisons and Proficiency Testing Uncertainty Tracebility Competence personnel Participation ILC s and PTS Approved Test and Calibration Methods 24 Quality Test and Calibration Results

25 ISO/IEC 17025:

26 Thank you for your attention! Any Questions? 26