Click here to load reader

PSD & Moisture Content - 2019 (86) PROFICIENCY TESTING ... LabS · PDF file 2.1.1, Determination of the moisture content of a soil – Oven drying method. The program provides confidence

  • View
    3

  • Download
    0

Embed Size (px)

Text of PSD & Moisture Content - 2019 (86) PROFICIENCY TESTING ... LabS · PDF file 2.1.1,...

  • www.labsmartservices.com.au

    PSD & Moisture Content - 2019 (86)

    PROFICIENCY TESTING

    PROGRAM REPORT

    Accredited for compliance with ISO/IEC 17043

    Copyright: LabSmart Services Pty Ltd

    PSD & Moisture Content - Proficiency Testing Program - 2019 (86)

    Copyright: LabSmart Services Pty Ltd Issued - May 2019 Page 1 of 47

  • Report This report is available on the LabSmart Services website. The issue of this proficiency report was authorised by Peter Young, Director, LabSmart Services Pty Ltd, May 2019. Contact Details

    Email: [email protected] Mobile: 0432 767 706 Fax: (03) 8888 4987

    Program Coordinator The program coordinator for this program was Peter Young, Director, LabSmart Services Pty Ltd. Contact Details

    Email: [email protected] Mobile: 0432 767 706 Fax: (03) 8888 4987

    Please note that any technical questions regarding this program are to be directed to the program coordinator.

    Z-scores Summary A z-scores summary for this program was issued in 28 April 2019. This technical report supersedes the z-sores summary.

    Accredited Proficiency Testing Provider LabSmart Services is accredited by NATA to ISO/IEC 17043, Conformity assessment – General requirements for proficiency testing. Accreditation number 19235. The accreditation provides additional assurance to participants of the quality and importance we place on our proficiency testing programs.

    LabSmart Services Further information regarding LabSmart Services proficiency testing programs can be found on our website.

    www.labsmartservices.com.au

    Copyright This work is copyright. No part of this publication may be reproduced in any form, transmitted or stored in any repository (e.g. mechanical, digital, electronic or photographic) without prior written permission of LabSmart Services Pty Ltd. Please contact LabSmart Services should you wish to reproduce any part of this report.

    Amendment History Reports may be downloaded from the LabSmart Services website.

    Version 1 – Issued 21 May 2019

    PSD & Moisture Content - Proficiency Testing Program - 2019 (86)

    Copyright: LabSmart Services Pty Ltd Issued - May 2019 Page 2 of 47

  • CONTENTS PAGE

    1. Program Aim

    4

    2. Performance?

    2.1 Identified Outliers 2.2 Overall Performance

    4

    4 5

    3. Technical Comment

    3.1 Material less than 75 µm (Washed) 3.2 Particle size distribution 3.3 Moisture content

    8

    8 10 14

    4. Material finer than 75 µm (Washed)

    4.1 Z-Scores & Graph

    16

    16

    5. Particle Size Distribution (% Passing)

    5.1 Z-scores & graph for 2.36 mm sieve 5.2 Z-scores & graph for 1.18 mm sieve 5.3 Z-scores & graph for 600 μm sieve 5.4 Z-scores & graph for 425 μm sieve 5.5 Z-scores & graph for 300 μm sieve 5.6 Z-scores & graph for 150 μm sieve 5.7 Z-scores & graph for 75 μm sieve

    18

    18 20 22 24 26 28 30

    6. Moisture Content

    6.1 Z-Scores & Graph

    32

    32

    7. Program Information

    7.1 Z-Score Summary 7.2 Program Design 7.3 Sample Preparation 7.4 Packaging and Instructions 7.5 Quarantine 7.6 Sample Despatch 7.7 Homogeneity Testing 7.8 Participation 7.9 Statistics 7.10 Non-statistical Matters

    34

    34 34 37 38 38 38 38 40 40 42

    Appendix A Instructions for testers Appendix B Results log Appendix C Participant results

    43

    45

    46

    PSD & Moisture Content - Proficiency Testing Program - 2019 (86)

    Copyright: LabSmart Services Pty Ltd Issued - May 2019 Page 3 of 47

  • 1. Program Aim The proficiency program was conducted in March/April 2019 with thirty-three participants throughout Australia. The program involved the performance of AS 1289 3.6.1, Determination of the particle size distribution of a soil and AS 1289 2.1.1, Determination of the moisture content of a soil – Oven drying method.

    The program provides confidence to the construction materials testing industry regarding the competency of participants (and the industry) to perform these tests. Each participant’s performance is statistically assessed and used as a measure of competency relative to all those who participated. Other measures of performance may also be used. This report has been prepared using robust statistics. Information regarding the conduct and design of the program can be found in section 7. Comprehensive technical comment (section 3) is provided to assist participants improve the overall performance of these tests. In addition, test data has been reviewed for consistency and additional feedback regarding aspects of the test are provided.

    2. How well did we perform? 2.1 Identified Outliers The results and statistical analysis of participant’s; Material less than 75 μm (washed) results, PSD results and moisture content results are detailed in sections 4,5 and 6 respectively. There were 14 outliers identified across the tests performed. These were spread across 5 participants. This represented 15% of the 33 participants (1,2) who returned results in the proficiency program (Table 2.1A). Participant’s test results are tabulated in sections 4, 5 and 6 along with the robust statistics and z-score graphs. The z-score indicates how far away a participant is from the program’s median value. A z-score of zero indicates a strong consensus with respect to all other participants and represents a very good outcome. The z-score graph gives a quick visual indication of how a result compares to others in the program. Outliers are where a z-score value is equal to or greater than 3 or less than or equal to -3. It is strongly recommended that participants with outliers investigate their performance of the test. Participants with outliers are detailed in table 2.1A. Those participants with z-scores greater than 2 or less than -2 should review their testing methodology. Only those approaching a z-score of 3 (i.e. outside ± 2.75) have been specifically identified in table 2.1A as feedback. More detail on the robust statistics used can be found in section 7.

    PSD & Moisture Content - Proficiency Testing Program - 2019 (86)

    Copyright: LabSmart Services Pty Ltd Issued - May 2019 Page 4 of 47

  • Technical comment and feedback in section 3 is provided to assist participants investigate or review their results as well for those seeking to improve their testing performance.

    Table 2.1A Participant codes where remedial action is recommended based on z-scores. Those with a z-score that was close to 2.75 should review their results. See section 3 for further comments.

    2.2 Overall Performance Overall a satisfactory level of performance (1) was achieved by the majority (85%) of participants with 15% having one or more outliers (2). The performance by participants is very good overall and compares favourably with previous proficiency programs. Different soil samples will yield different variation for each fraction according to material quantity and type. The performance by participants is consistent with previous programs. The variation in test results in this program are similar to those of previous programs as summarised in table 2.2A. This is a good outcome. Competency of washing was assessed through the calculation of a ‘washed material finer than 75 μm’ result. Although not a reportable result under the test method the mass of the washed material is still accountable within the test and competency of washing is an important aspect of the test. Most participants completed the washing satisfactorily. The spread in results for ‘washed - material finer than 75 μm’ was very good. There is an opportunity for laboratories to improve. The data indicates that there is considerable room for improvement in the use of ‘check sums’ and the checking process employed by technicians and supervisors.

    Sample Test Investigate Review

    A

    Less than 75 µm (by washing) - -

    Particle size distribution (% Passing)

    2.36 mm G4 -

    1.18 mm G4 -

    600 μm G4 -

    425 μm G4 B9

    300 μm G4, K7 -

    150 μm G4, K7, X8 -

    75 μm K7, X8 -

    B Moisture content K7, B9, X2 -

    PSD & Moisture Content - Proficiency Testing Program - 2019 (86)

    Copyright: LabSmart Services Pty Ltd Issued - May 2019 Page 5 of 47

  • There was a significant number of errors made by participants in the calculations (based on data provided and assumed to be correct). In many cases this often caused a poorer outcome. In other instance it threw doubt on some outcomes, that when recalculated, may have resulted in outliers. It is something laboratories should continue to work towards improving.

    Table 2.2A Comparison of performance outcomes over the last five programs.

    The determination of moisture content (Sample B) by participants was very good with a very low standard derivation. A very good outcome. Section 3 provides technical comment which may be useful in identifying possible areas for i

Search related