FINAL REPORT

Transcription

1 PROFICIENCY TESTING PROGRAMME FOR CHEMICAL TESTING OF ZINC ALLOY [PTM/CHEM/04/14-15] FINAL REPORT ORGANIZED BY GLOBAL PT PROVIDER PVT. LTD., NEW DELHI PT SCHEME NAME : CHEMICAL TESTING OF ZINC ALLOY PT SCHEME CODE : PTM/CHEM/04/14-15 PT REPORT NO. : C04RT/15/R-01 DATE OF ISSUE : 08/08/2015 AUTHORISED BY : MR. UMESH GUPTA (TECHNICAL DIRECTOR) Page 1 of 24

2 PT PROVIDER DETAILS NAME & ADDRESS OF THE PROFICIENCY TESTING PROVIDER: GLOBAL PT PROVIDER PRIVATE LIMITED E-41, OKHALA INDUSTRIAL AREA, PHASE II NEW DELHI , INDIA TEL: , , COORDINATORS OF THE PROFICIENCY TESTING PROGRAMME: MR. RAM TIRATH PT COORDINATOR ADVISORY GROUP OF THE PROFICIENCY TESTING PROGRAMME: MR. KULDEEP DHINGRA REPORT PREPARED BY REPORT CHECKED BY REPORT AUTHORISED BY MR. ASIM DASH MR. RAMTIRTH MR. UMESH GUPTA PT COORDINATOR MANAGER (QA) TECHNICAL DIRECTOR Page 2 of 24

3 CONTENTS S. No. Description Page No. 1. Cover Page 1 2. PT Provider Details 2 3. Contents 3 4. Abbreviations used 4 5. Introduction 5 6. Objectives of Proficiency Testing 5 7. Design of PT Scheme 6-9 PT Programme Schedule Preparation of PT Items Parameters for the PT Scheme Homogeneity Testing Distribution of PT Items Stability Testing Submission of Results Analysis of Result 8. Subcontracted Activities 9 9. Confidentiality in Proficiency testing Summary of Results [Data Tables] Robust Z-Score Chart: Lab Code Vs Z Score Outlier Results References: Intimation Letter (Annexure: I) Participant Instruction Sheet (Annexure: II) Sample Receipt Form ((Annexure: III) Result Sheet (Annexure: IV) Laboratory Summary Sheet (Annexure: V) Page 3 of 24

4 ABRIVIATION USED PT NABL ISO IEC PTM CHEM H & S Al Mg Cu Pb Ni Fe Sn PROFICIENCY TESTING NATIONAL ACCREDITATION BOARD FOR TESTING AND CALIBRATION LABORATORY INTERNATIONAL ORGANISATION FOR STANDARDISATION INTERNATIONAL ELECTROTECHNICAL COMMISSION PROFICIENCY TESTING PROGRAMME IN METAL CHEMICAL HOMOGENEITY AND STABILITY ALUMINIUM MAGNESIUM COPPER LEAD NICKEL IRON TIN Page 4 of 24

5 INTRODUCTION Proficiency Testing has become an essential aspect of laboratory practice in all areas of testing, calibration and inspection. Participation in proficiency testing schemes provides laboratories with an objective means of assessing and demonstrating the reliability of the data they are producing. One of the main uses of PT scheme is to assess laboratories ability to perform test competently. This report summarizes the results of Proficiency Testing programme on chemical composition of Zinc Alloy. The elements determined in this programme are Aluminium, Magnesium, Copper, Lead, Nickel, Iron & Tin. The chemical composition of Zinc alloy is routine analysis items for most laboratories. The function of the testing laboratories is to provide data. On the basis of this data the decision are made in the Trade and Commerce industry. Thus, the reliability of test data in the laboratories can provide quality services and practicing good quality management system. The results from Proficiency Testing Programme are useful to both participating laboratories and accreditation bodies. Successful participation in a specific proficiency testing programme may represent evidence of competence for that exercise. Similarly, unsuccessful performance may reflect a random departure from a laboratories normal state of competence. OBJECTIVES OF PROFICIENCY TESTING The main objective of the programme was to evaluate the performance of participating laboratories in the analysis of Zinc alloy for the content Aluminium, Magnesium, Copper, Lead, Nickel, Iron & Tin by means of inter-laboratory comparison. Test results from participants are evaluated according to the statistical techniques outlined in ISO 13528:2005 Statistical methods for use in proficiency testing by inter laboratory comparisons. The z- score is used as a numerical indicator to assess individual participant s performance in the programme. Page 5 of 24

6 No. of Days PT Scheme: Chemical Testing of Zinc Alloy PARTICIPANTS Invitation of Proficiency Testing was done through Intimation Letter as given in annexure I. Participants have sent their consent by submitting dully filled Registration form. PT samples were sent to each laboratory after their registration for this programme. Participants were advised to carry out testing of PT sample as soon as possible after receiving samples as per standard test method. The PT sample is to be treated by laboratory in the same way as routine laboratory samples. 12 laboratories have participated in this PT programme. DESIGN OF PROFICIENCY TESTING SCHEME PT PROGRAMME SCHEDULE: TABLE 1: PT PROGRAMME SCHEDULE S. No. PT Activities Actual PT Schedule 1. Invitation & Registration 01 th Feb to 15 th May Preparation of Raw Material 20 th Mar to 15 th Apr Material Verification 20 th Apr to 24 th Apr Sample Preparation 26 th Apr to 02 nd May Homogeneity Testing & Evaluation 04 th May to 12 th May Sample Dispatch 22 th May to 26 th June Stability Testing 23 rd May to 14 th July Result Received 25 th May to 14 th July Data Analysis 16 th July to 28 th July Draft Report 03 rd Aug to 06 th Aug Final Report Generation & Distribution 07 th Aug to 10 th Aug PT Programme Schedule Invitation & Registration Preparation of Raw Material Material Verification Sample Preparation Homogeneity Testing & Evaluation Sample Dispatch PT Activities Stability Testing Result Received Data Analysis Draft Report Final Report Generation & Distribution Page 6 of 24

7 PREPARATION OF PT ITEMS: A lot 100 kg is prepared from the virgin metals. Pure Zinc of purity 99.9% and other pure metals Like Copper, Aluminum, Magnesium, Lead, Tin and Iron are added to prepare off grade Zamak-5. The melting is done in induction furnace to attain the desired homogeneity. The material was casted in the form of rod of 40mm diameter. Chemical compositions of 6 samples from Zinc rod were analyzed using optical emission PARAMETERS FOR THE PT SCHEME: TABLE 2: PARAMETERS FOR THE PT SCHEME S. No. Test Parameter Test Method Suggested Range of Testing 1. ALUMINIUM (AS Al), % OES/AAS METHOD 3-5% 2. MAGNESIUM (AS Mg), % OES/AAS METHOD % 3. COPPER (AS Cu), % OES/AAS METHOD % 4. LEAD (AS Pb), % OES/AAS METHOD % 5. NICKEL (AS Ni), % OES/AAS METHOD % 6. IRON (AS Fe), % OES/AAS METHOD % 7. TIN (AS Sn), % OES/AAS METHOD % HOMOGENEITY TESTING: Homogeneity Testing was subcontracted to NABL Accredited Laboratory. 20 samples were randomly selected from total samples. These samples were analyzed for the chemical composition using optical emission spectrometer. Two sparks were taken on the individual sample. The Analysis of Variance for homogeneity test (ANOVA) & Annexure-B of ISO 13528:2005 were used for examining the homogeneity of the test material. DISTRIBUTION OF PT ITEMS: Participating laboratories were supplied one sample of 40X25mm. The samples were packed in plastic container with Sponge & bubble. Samples were distributed to the participant by speed post and courier. Conformation of sample receipt was ensured through the return receipt of duly filled Sample Receipt Form from each participant. Participation Instruction Sheet and Receipt Form are given in Annexure II & III respectively. STABILITY TESTING: Stability Testing was subcontracted to NABL Accredited Laboratory. 6 samples were randomly selected in the month of May, June & July for chemical composition. The stability of the PT samples was checked as per Annexure-B of ISO 13528:2005. Page 7 of 24

8 SUBMISSION OF RESULTS: Participants were requested to perform the test according to the Instruction Sheet (Annexure II) and to submit their laboratories test results to the accuracy specified in the result sheet (Annexure IV). Reporting of test results were to be done by each parameter. In case of laboratory does not carry out of the specified parameters then indicate the same by marking the result columns for these parameters, with cross/any other mark. The results of the individual laboratories were received through duly filled Result Sheet format. The original data is tabulated in (TABLE 3-8). ANALYSIS OF DATA: In order to maintain the confidentiality of the participants of the PT Scheme, the individual participant laboratories were given unique Lab Code numbers in result sheet format. Robust Average is calculated from submitted results and used as assigned value as per ISO 13528:2005. Robust Z score has been analyzed as per ISO 13528:2005 for each laboratory for each parameter to keep the result free from disturbances due to the extreme values. DETERMINATION OF ASSIGNED VALUE: The Assigned values, x* and standard deviation of proficiency testing, s*( σ ) were derived from the consensus of the results submitted by the participants (Algorithm A, Annexure C of ISO 13528: 2005). No results were excluded from the calculation of assigned value. PERFORMANCE EVALUATION OF PARTICIPANTS: The performance of the individual laboratory was evaluated by adopting Robust Z score technique given in ISO 13528:2005, as per the following formula: Z = x X σ Where, x is the test result reported by the individual laboratory X is the Assigned Value & σ is the standard deviation of the Proficiency Assessment. INTERPRETATION OF THE PERFORMANCE: The calculated Z-scores are tabulated in the report alongside the corresponding results and the results are assessed based on their Z-Scores. The results of Z-Score are interpreted as follows. Page 8 of 24

9 Z < 2 = Satisfactory 2 < Z < 3 = Questionable Z > 3 = Unsatisfactory. An Outlier defined as any results / pair of results with an absolute Z-Score greater than 3 i.e. Z >3 or Z<-3. The outlier criteria Z > 3 has a confidence level of about 99.73% i.e. there is less than 1% chance that the result is a true member of the population and it is for more likely that there is a problem with this result/ pair of result. Laboratories which have a Z-Score in the region 2 < 3 are encouraged to take a close look at their results. However the sign of the value of Z-Scores must be considered. The value > 3 indicate the both of results for pair is too high. Similarly negative (-3) indicates the results are too low. SUBCONTRACTING ACTIVITIES The following activities have been subcontracted for this PT programme as given below: Material Testing Sample Preparation Homogeneous Testing CONFIDENTIALITY IN PROFICIENCY TESTING In order to maintain confidentiality of participants of the PT scheme, each participant laboratories are given unique Lab ID which is only disclosed to that participant. Participant identity, performance and report will not be disclosed to any other party without the prior permission of the participants and written authorisation. Confidentiality will be maintained at all levels. The results of the PT can be disclosed to Accreditation/Regulatory body. CONCLUSION Total 12 nos. laboratory has participated in this PT programme. All twelve laboratories have participated in all the seven parameters. Out of twelve laboratories seven laboratories have satisfactorily results in all the six parameters. The no. of unsatisfactorily results from the laboratories in Aluminium, Magnesium, Copper, Lead, Nickel & Tin are 0, 1, 0, 0, 1 & 2 respectively. The no. of questionable results from the laboratories in Aluminium, Magnesium, Copper, Lead, Nickel & Tin are 0, 1, 0, 2, 0 & 2 respectively. Due to insufficient data the Z score of Iron could not be evaluated. Page 9 of 24

10 SUMMARY OF RESULTS [DATA TABLES] Page 10 of 24

11 TABLE 3: ROBUST Z-SCORE FOR ALUMINIUM Aluminium (as Al) Lab Code Reported Value (%) Test Method Adopted Z Score Performance Zn ISAPL/SOP/02/L 0.79 Satisfactory Zn OES Satisfactory Zn AAS Satisfactory Zn IS:2599: Satisfactory Zn OES 0.26 Satisfactory Zn MAT/SOP/S Satisfactory Zn OES 0.74 Satisfactory Zn ICP-OES 1.38 Satisfactory Zn ASTM E Satisfactory Zn AAS Satisfactory Zn SO-IN-CTS-C06-MET Satisfactory Zn IS:2599: Satisfactory Total No. of Participants 12 Maximum Reported Value (%) 4.05 Minimum Reported Value (%) 3.42 Robust Average (%) 3.79 Standard Deviation of Proficiency Testing (σ) 0.19 Page 11 of 24

12 TABLE 4: ROBUST Z-SCORE FOR MAGNESIUM Magnesium (as Mg) Lab Code Reported Value (%) Test Method Adopted Z Score Performance Zn ISAPL/SOP/02/L 0.01 Satisfactory Zn OES Satisfactory Zn AAS Satisfactory Zn IS:2599: Unsatisfactory Zn OES 0.01 Satisfactory Zn MAT/SOP/S Satisfactory Zn OES Questionable Zn ICP-OES 0.92 Satisfactory Zn ASTM E Satisfactory Zn AAS Satisfactory Zn SO-IN-CTS-C06-MET Satisfactory Zn IS:2599: Satisfactory Total No. of Participants 12 Maximum Reported Value (%) Minimum Reported Value (%) Robust Average (%) Standard Deviation of Proficiency Testing (σ) Page 12 of 24

13 TABLE 5: ROBUST Z-SCORE FOR COPPER Copper (as Cu) Lab Code Reported Value (%) Test Method Adopted Z Score Performance Zn ISAPL/SOP/02/L 1.04 Satisfactory Zn OES 1.63 Satisfactory Zn AAS Satisfactory Zn IS:2599: Satisfactory Zn OES Satisfactory Zn MAT/SOP/S Satisfactory Zn OES Satisfactory Zn ICP-OES 0.46 Satisfactory Zn ASTM E Satisfactory Zn AAS Satisfactory Zn SO-IN-CTS-C06-MET Satisfactory Zn IS:2599: Satisfactory Total No. of Participants 12 Maximum Reported Value (%) 1.20 Minimum Reported Value (%) 0.94 Robust Average (%) 1.06 Standard Deviation of Proficiency Testing (σ) 0.08 Page 13 of 24

14 TABLE 6: ROBUST Z-SCORE FOR LEAD Lead (as Pb) Lab Code Reported Value (%) Test Method Adopted Z Score Performance Zn ISAPL/SOP/02/L Satisfactory Zn OES Satisfactory Zn AAS 0.68 Satisfactory Zn IS:2599: Satisfactory Zn OES Satisfactory Zn MAT/SOP/S Satisfactory Zn OES 1.04 Satisfactory Zn ICP-OES 0.33 Satisfactory Zn ASTM E Questionable Zn AAS 0.68 Satisfactory Zn SO-IN-CTS-C06-MET Questionable Zn IS:2599: Satisfactory Total No. of Participants 12 Maximum Reported Value (%) Minimum Reported Value (%) Robust Average (%) Standard Deviation of Proficiency Testing (σ) Page 14 of 24

15 TABLE 7: ROBUST Z-SCORE FOR NICKEL Nickel (as Ni) Lab Code Reported Value (%) Test Method Adopted Z Score Performance Zn ISAPL/SOP/02/L Satisfactory Zn OES 1.40 Satisfactory Zn AAS Satisfactory Zn-04* IS:2599: Unsatisfactory Zn OES 0.77 Satisfactory Zn MAT/SOP/S Satisfactory Zn OES Satisfactory Zn ICP-OES 0.31 Satisfactory Zn ASTM E Satisfactory Zn AAS 0.13 Satisfactory Zn SO-IN-CTS-C06-MET Satisfactory Zn IS:2599: Satisfactory Total No. of Participants 12 Maximum Reported Value (%) Minimum Reported Value (%) Robust Average (%) Standard Deviation of Proficiency Testing (σ) *Result of this laboratory has been discarded due to suspicious value Page 15 of 24

16 TABLE 8: ROBUST Z-SCORE FOR TIN Lab Code Reported Value (%) Tin (as Sn) Test Method Adopted Z Score Performance Zn ISAPL/SOP/02/L Satisfactory Zn OES 0.96 Satisfactory Zn AAS 1.30 Satisfactory Zn IS:2599: Unsatisfactory Zn OES Questionable Zn MAT/SOP/S Satisfactory Zn-07* OES 6.71 Unsatisfactory Zn ICP-OES 0.96 Satisfactory Zn ASTM E Satisfactory Zn AAS 0.63 Satisfactory Zn SO-IN-CTS-C06-MET Questionable Zn IS:2599: Satisfactory Total No. of Participants 12 Maximum Reported Value (%) Minimum Reported Value (%) Robust Average (%) Standard Deviation of Proficiency Testing (σ) *Result of this laboratory has been discarded due to suspicious value Page 16 of 24

17 ROBUST Z- SCORE CHART: LAB CODE VS Z-SCORE Page 17 of 24

18 Zn-11 Zn-03 Zn-13 Zn-04 Zn-10 Zn-02 Zn-05 Zn-07 Zn-09 Zn-01 Zn-06 Zn-08 PT Scheme: Chemical Testing of Zinc Alloy Aluminium (Al) 3.00 Aluminium (as Al) Graph Aluminium (as Al) Graph 2 Red Color Indicates Outlier Pink Color Indicates Questionable Green Color Indicates Satisfactory Page 18 of 24

19 Zn-07 Zn-09 Zn-10 Zn-02 Zn-03 Zn-06 Zn-01 Zn-05 Zn-08 Zn-13 Zn-11 Zn-04 PT Scheme: Chemical Testing of Zinc Alloy Magnesium (Mg) 5.00 Magnesium (as Mg) Graph Magnesium (as Mg) Graph 4 Red Color Indicates Outlier Pink Color Indicates Questionable Green Color Indicates Satisfactory Page 19 of 24

20 Zn-11 Zn-07 Zn-10 Zn-09 Zn-03 Zn-05 Zn-04 Zn-13 Zn-08 Zn-01 Zn-06 Zn-02 PT Scheme: Chemical Testing of Zinc Alloy Copper (Cu) 3.00 Copper (as Cu) Graph Copper (as Cu) Graph 6 Red Color Indicates Outlier Pink Color Indicates Questionable Green Color Indicates Satisfactory Page 20 of 24

21 Zn-11 Zn-13 Zn-04 Zn-05 Zn-01 Zn-02 Zn-06 Zn-08 Zn-03 Zn-10 Zn-07 Zn-09 PT Scheme: Chemical Testing of Zinc Alloy Lead (Pb) 4.00 Lead (as Pb) Graph Lead (as Pb) Graph 8 Red Color Indicates Outlier Pink Color Indicates Questionable Green Color Indicates Satisfactory Page 21 of 24

22 Zn-11 Zn-01 Zn-13 Zn-03 Zn-07 Zn-10 Zn-08 Zn-06 Zn-05 Zn-02 Zn-09 PT Scheme: Chemical Testing of Zinc Alloy Nickel (Ni) 3.00 Nickel (as Ni) Graph Nickel (as Ni) Graph 10 Red Color Indicates Outlier Pink Color Indicates Questionable Green Color Indicates Satisfactory Page 22 of 24

23 Zn-04 Zn-05 Zn-11 Zn-13 Zn-01 Zn-09 Zn-06 Zn-10 Zn-02 Zn-08 Zn-03 PT Scheme: Chemical Testing of Zinc Alloy Tin (sn) 2.00 Tin (as Sn) Graph Tin (as Sn) Graph 12 Red Color Indicates Outlier Pink Color Indicates Questionable Green Color Indicates Satisfactory Page 23 of 24

24 OUTLIER RESULTS Overall 12 Laboratories have participated in this proficiency testing programme and the results are given below in tabulated form TABLE 12: OUTLIER RESULTS SUMMARY S. No. Test Parameters No. of Results Questionable Outlier 1. Aluminium (as Al), % 12 Nil Nil 2. Magnesium (as Mg), % Copper (as Cu), % 12 Nil Nil 4. Lead (as Pb), % 12 2 Nil 5. Nickel (as Ni), % 12 Nil 1 6. Tin (as Sn), % In case the Performance of the laboratory in the proficiency testing is not found satisfactory, the laboratory should find out its causes of inadequacy. Once the causes are analyzed it would be possible for the laboratory to identify the number of areas where improvement is needed. Page 24 of 24