STATISTIQUE DE PERFORMANCE

Transcription

1 INTERCOMPARISON OF STANDARD CALIBRATION, METHODS AND MEASUREMENTS FOR PRESSURE, TEMPERATURE AND HUMIDITY BETWEEN RIC CASABLANCA, MOROCCO AND RIC Ljubljana SLOVENIA 3(10) The operators who participated in the calibration relating to this comparison are: - Mr. Mounir AZIZ: RIC Responsible, Casablanca Morocco - Mr. Ales Razpotnic: Pression Field, Slovenian Environment Agency - -Mr. Drago Groselj, RIC Responsible, Slovenian Environment Agency, drago.groselj@gov.si ABSTRACT A CIL (Comparison interlaboratory) of standard calibration instruments and methods for pressure, humidity and temperature was organised in 2015 between the laboratories of metrology of Meteo Morocco and the Slovenian Environment Agency. The two RIC laboratories are equipped and work identically in terms of equipments and methods. Both laboratories use the ISO 17025:2005 standard and have an unbroken chain of traceability of their standards. The results show and prove an agreement between the measurements from the laboratories for both pressure, temperature and humidity calibration.

2 1. Introduction 3 2. REFERENCE DOCUMENTS 3 3. Instrument used 3 4. Program and pressure calibration procedures: 3 5. Diagram measurement benches mounting pressure: 3 6. RESULALTS: Uncertainties: Drift values obtained from testing: 5 7. STATISTIQUE DE PERFORMANCE 6 8. ERRORS DUE TO TRANSPORTATION : 7 9. Conclusion: 7

3 1. INTRODUCTION This paper presents the results of the comparison inter laboratory for calibration of barometers, between the laboratories of Moroccan Meteorology Department and Slovenian Environment Agency, performed on the occasion of Expert Team on Operational Metrology (ET OM) meeting in Ljubljana, Slovenia, from 1st 4th December 2015, hosted by Regional Instrument Center of the Slovenian Environment Agency. The first calibrations were made in Morocco on November 30, 2015, and return on March 1, 2016, the calibration by Slovenian Environment Agenc, took place on 3 and 4 December Interlaboratory comparison (ILC) serves as a tool for comparison of measurement results carried out by both calibration laboratories in the field of Pressure, temperature and humidity measurement. ILC represents the best means to demonstrate technical competence of the participant and also serves as a part of technical bases for accreditation, it is the most important element for monitoring of quality of measurement results as required by ISO/IEC 17025:2005 standard for laboratories in part REFERENCE DOCUMENTS The certificates produced or used in this comparison are: The calibration certificate No Labo. Slovenia and the certificate No. CEP15170 Labo. Morocco. The labo. Morocco joined his traceability certificate (Cal Cert ID: 121,595 in the accredited Mensor laboratory Cert ZL. 3. INSTRUMENT USED The instrument calibrated by both laboratories is: In Calibration pressure: Display PTB 330 barometer (VAISALA), Serial C PROGRAM AND PRESSURE CALIBRATION PROCEDURES: The laboratory of Slovenian Environment Agency calibrated on its own calibration bench with a standard traceable to the international system, the calibration was done in 11 points between 850 hpa and 1100 hpa. Three down climb cycles were applied for 2 Slovénen and Moroccan laboratories, with bearings 2500 Pa. The Morocco Laboratory calibrate the barometer compared to its generator and reference standard "MENSOR CPC 6000" in 11 points from Pascal to pascal. 5. DIAGRAM MEASUREMENT BENCHES MOUNTING PRESSURE: Installation diagrams of two laboratories are fairly similar, but with two different brands.

4 calibration bench assembly diagram of Moroccan laboratory, with integrated standard automatic generator CPC6000 POMPE PC Baromètre réf : pression PPC1 Générateur A Z O T E Liaison série Circuit pneumatique Alimentation secteur Distributeur de pression calibration bench assembly diagram of Slovenian laboratory Baromètre à étalonner 6. RESULALTS:

5 The results of calibrations used for intercomparison, are averages of three cycles of correction term measures, accompanied by the uncertainty calculated for each calibration laboratory and according to the means used. The ambient conditions in laboratory of Slovenia is 22 C to 25.5 C with a relative humidity between 25% and 32%; and in the laboratory of Morocco is 23 C to 23.6 C Uncertainties: Both laboratories express calibration uncertainty with a coverage factor k = 2 And take into account four important components: Uncertainty calibration means Uncertainty due to the repeatability of the sensor at 3 cycles, The maximum hysteresis observed for all of the bearings. The uncertainty due to the resolution of the instrument under test Laboratory of Slovenian Environment Agency declared uncertainties are set at the maximum pressure used = 1100 hpa. This method simplifie the use of uncertainty whereas the range of maximum pressure measurements (850 to 1100 hpa) does not justify the method of polynomial calculation and the discrepancies between the low pressure and considered high pressure, are small compared to the overall uncertainty. Details uncertainties determined by the two laboratories: Laboratory Slovenia ( Pa) Laboratory Morocco ( Pa) u -moyens / 2 u -moyens / 2 U= 1,5 Pa + 3,3 *10-5 * P u- répétabilité u- répétabilité 3 u_ hyster ptb u_ hyster ptb 0.005/ 3=0,289 u_ resolution ptb u_ resolution ptb 0.005/ 3=0,289 U (k=2) = 8 Pa U(k=2) = 6 Pa + 2*10-3 P soit au max. = 8,2 Pa Slovénie : 2* Root (u -moyens 2 +u -répétabilité2 +u _hyster_ptb 2 +u _resolution_ptb2 ) U = 8 Pa Maroc : 2*Root (u -moyens 2 +u -répétabilité 2 +u _hyster_ptb 2 +u _resolution_ptb 2 ) U = (6 Pa +2*10-3 P) = 8,2 Pa The error means the maximum difference observed between the standard and the test sensor. Tolerance or compliance of customer, declared by the Moroccan Laboratory is 0,5 mbar or 50 Pa The decision criterion is "the greater error (E Accuracy, Fidelity E, E hysteresis) increased the uncertainty (U) must be less than the specified tolerance. Ei + U <(T / 2), T = customer tolerance Similarly, the adjustment criterion in test barometers established by the formula Error + U <( C / 2), C = Customer Compliance = T 6.2. Drift values obtained from testing:

6 All the points of steps executed by Laboratory Slovenia and Laboratory Morocco is reported in this table, where measurements are made using the same bearings are analyzed. SETPOINTS (Pa) UNCERTAINTY U (Pa) Morocco Slovenia U Maroc U Slovénie Réf = Pe Pe-Pi Réf = Pe Pe-Pi , , , , , , , , , , , , , , , ,2 8 Comparative curves in Pascal Note that the sensor used, presents a gap between 32 and 33Pa for the values obtained by Laboratory Slovenia and 30.5 and 36 Pa to the values obtained by Laboratory Morocco. The uncertainty bars are representative of U declared 8 Pa Laboratory Slovenia and between 7.7 and 8.2 for Laboratory Morocco, these error bars show the overlay measurements of this sensor by 2 calibration methods. To this end, it seems necessary to calculate the standard deviation of all measurements, to check whether the inter comparison pressure is considered satisfactory. 7. STATISTIQUE DE PERFORMANCE Performance statistic used in the context of this intercomparison is the standard deviation "EN"; described according to DIN EN ISO / IEC 17043: It is obtained as follows: En M S / (U M U S )

7 X M and X S are the results, respectively, error indications or corrections of participating laboratory from morocco and slovenia. U Labi et U Labp are respectively the expanded uncertainties of participating laboratory from morocco and slovenia. ERRORS MOROCCO SLOVENIA Ecarts = M U Ecarts = S U EN Maroc Slovenie 34 7, , , ,09 33,5 7, , , ,09 31,5 7, ,04 30,5 7, , ,00 33, , , ,26 34,5 8, , , ,26 8. ERRORS DUE TO TRANSPORTATION : SETPOINTS DERIVE /REF DERIVE/REF BEFORE AFTER DRIFT UP DOWN UP DOWN UP DOWN For the travel of the sensor, calibration report shows excellent retention of the equipment after transportation, the maximum deviation is 5 Pascal between calibrations values before and after transport. 9. CONCLUSION:

8 RESULTATS DE L INTER COMPARAISON PRESSION EN-S Version: A Date: 14/08/2013 In this case comparing two laboratories and in particular for the pressure calibration method, it is found that the values obtained by the two laboratories have a superposition inducing a good agreement. The standard deviation is well below the limit value of 1. The comparison is satisfactory. Both laboratories have unbroken traceability chains for humidity and pressure and their calibration results are in good agreement. Full results will be available at TECO2016.