4/28/2014 Evaluation of Cottonscope precision for module averaging Patrick Mileto and Stuart Gordon March 18 th 2014 CSIRO – MATERIALS SCIENCE AND ENGINEERING Introduction This work examines the sampling required to measure Cottonscope values with an acceptable degree of precision. The application is aimed at ‘high volume’ instrument testing and particularly at the variation seen between successive bales from the same module. Precision defined in terms of relative error is reported for Cottonscope values based on a module averaging sampling regime; i.e. one bale in three tested for a standard module. ICCTM ‐ 2014 | Mileto and Gordon | 1
4/28/2014 Materials 600+ bales ( ≈ 30 modules) each of low MIC (3.6) and standard MIC (4.2) cotton ginned, sampled and classed in succession. Samples tested by HVI and Cottonscope followed standard procedures. ICCTM ‐ 2014 | Mileto and Gordon | Precision in HVI Micronaire values using module averaging regime on irrigated, machine harvested cotton from same field 4.80 4.60 4.40 4.20 Micronaire (HVI) 4.00 3.80 3.60 3.40 3.20 3.00 0 200 400 600 800 1000 1200 Successive bales MIC HVI MIC HVI av 95%CI ‐ 95%CI+ 6 Periode gleit. Mittelw. (MIC HVI) ICCTM ‐ 2014 | Mileto and Gordon | 2
4/28/2014 Precision in HVI MR values using module averaging regime on irrigated, machine harvested cotton from same field 0.890 0.880 0.870 0.860 MR (HVI) 0.850 0.840 0.830 0.820 0.810 0.800 0 200 400 600 800 1000 1200 Successive bales MR HVI MR HVI av 95%CI ‐ 95%CI+ 6 Periode gleit. Mittelw. (MR HVI) ICCTM ‐ 2014 | Mileto and Gordon | 1 in 3 bales tested by HVI 1 bale = 1 HVI test specimen (100 – 200 g) Cotton ‘Run’ mean Range of Range of Mean relative error 1 in ‘module’ ‘module’ means ‘module’ SEs average ‘Low’ MIC 3.57 3.46 – 3.72 0.04 – 0.08 2.8% ‘Standard’ MIC 4.16 4.04 – 4.41 0.05 – 0.12 3.7% ‘Low’ MR 0.846 0.840 – 0.854 0.000 – 0.011 1.1% ‘Standard’ MR 0.867 0.861 – 0.871 0.000 – 0.006 0.8% Mean value of each ‘run’ represents 600+ successive bales from same field Mean value of each ‘module’ represents 15 ‐ 21 bales 1 Relative error = (95% confidence value around module std. error/module mean) x 100 ICCTM ‐ 2014 | Mileto and Gordon | 3
4/28/2014 Experimental – Cottonscope testing Consecutive Standard Low bale samples MIC MIC x 6 (1 module) cotton cotton Bale samples 1SS, 2SS, 5SS SS stored under std. are sub-sampled and 10SS taken conditions during (SS) per sample sampling Two test TS conditioned for specimens (TS) 12hrs under std. prepared from conditions each SS Cottonscope 2TS tested per SS ICCTM ‐ 2014 | Mileto and Gordon | Improvement in precision with multiple tests – Cottonscope FIN results for standard MIC cotton 260.0 250.0 Cottonscope FIN (mg/km ‐ mtex) 240.0 230.0 220.0 210.0 200.0 190.0 0 20 40 60 80 100 120 140 Test specimen number Test Mean 1SS (=2TS) Mean 2SS Mean 5SS Mean 10SS ICCTM ‐ 2014 | Mileto and Gordon | 4
4/28/2014 Improvement in precision with multiple tests – Cottonscope MR results for standard MIC cotton 0.900 0.890 Cottonscope MR 0.880 0.870 0.860 0.850 0 20 40 60 80 100 120 140 Test specimen number Test Mean 1SS (=2TS) Mean 2SS Mean 5SS Mean 10SS ICCTM ‐ 2014 | Mileto and Gordon | 1 in 3 bales tested by Cottonscope 1 bale = 1 sub ‐ sample (1SS), 2SS, 5SS or 10SS tested Relative error Relative error Relative error Relative error Cotton for ‘module’ for ‘module’ for ‘module’ for ‘module’ average 1SS average 2SS average 5 SS average 10SS ‘Low’ FIN (189 mtex) 6.8% 5.8% 4.3% 3.9% ‘Standard’ FIN (223 mtex) 7.5% 6.6% 6.2% 5.1% ‘Low’ MR (0.844) 1.2% 1.1% 1.0% 0.7% ‘Standard’ MR (0.878) 1.5% 1.2% 1.1% 0.8% ‘Low’ MIC (3.65) 4.8% 4.4% 4.3% 3.4% ‘Standard’ MIC (4.41) 3.9% 2.7% 2.6% 1.3% ‘Low’ WID (14.30 um) 0.8% 0.7% 0.6% 0.5% ‘Standard’ WID (14.28 um) 1.0% 0.9% 0.9% 0.7% 1SS = 2 test specimens (TS) = 100 mg of sample tested ICCTM ‐ 2014 | Mileto and Gordon | 5
4/28/2014 Conclusions Comparison HVI v. Cottonscope values Cotton HVI mean Mean relative Cottonscope Mean relative error 1 in ‘module’ error 1, 2 in mean 2 average ‘module’ average ‘Low’ MIC 3.57 2.8% 3.65 4.8% ‘Standard’ MIC 4.16 3.7% 4.41 3.9% ‘Low’ MR 0.846 1.1% 0.844 1.2% ‘Standard’ MR 0.867 0.8% 0.878 1.5% 1 Relative error = (95% confidence interval around module std. error/module mean) x 100 2 For one module only; error values represent 1 SS (2 x TS) per bale Cottonscope precision in measuring MIC and MR using 1 SS (2 x TS) per bale is similar to HVI MIC and MR using 1 test sample Cottonscope precision in measuring FIN can be improved by increasing the number of SS tested per sample; ± 15 mtex (1 SS) → ± 9 mtex (10 SS) ICCTM ‐ 2014 | Mileto and Gordon | Acknowledgements Sponsorship by Cotton Incorporated is gratefully acknowledged Patrick Mileto Lisa O’Brien ICCTM ‐ 2014 | Mileto and Gordon | 6
4/28/2014 Thank you CSIRO Stuart Gordon Research Group Leader Fibre Physics and Engineering t +61 3 5246 4809 E stuart.gordon@csiro.au w www.csiro.au CSIRO MATERIALS SCIENCE AND ENGINEERING 7
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