Figs. 5-6. Gage R&R studies were con- ducted for the spectrophotometry test (left) and the methylene blue clay test (right).
Based on common statistical
procedures, the range of accept- ability of a measurement system can be determined using the following guidelines. If the total Gage R&R percentage in the %Study Var col- umn (% tolerance, % process) is less than 10%, the measurement system is acceptable. If it is between 10% and 30%, the measurement system is acceptable depending on the appli- cation, cost of the measuring device, repair cost or other factors. If it is greater than 30%, the measurement system is not acceptable and should be revised.
If the %Contribution column is less than 1%, the measurement system is acceptable. If it is between 1% and 9%, the measurement system is acceptable depending on the application, repair cost, cost of the measuring device or other factors. If it is greater than 9%, the measure- ment system is unacceptable and should be improved. Both the indices are lower than 10% in the spectrophotometry technique (%Study Var = 5.54% and %Contribution = 0.31%). The indi- ces for the methylene blue test were %Study Var = 40% and %Contribu- tion = 16%. Te next phase of the research will
evaluate the effect of secondary green sand additives on the data.
Research for the alternative methylene blue clay test was endorsed by the AFS 4H committee. For the original paper (13-1455) presented on the test at the 117th Metalcasting Congress, go to
www.moderncasting.com.
August 2013 MODERN CASTING | 39
Page 1 |
Page 2 |
Page 3 |
Page 4 |
Page 5 |
Page 6 |
Page 7 |
Page 8 |
Page 9 |
Page 10 |
Page 11 |
Page 12 |
Page 13 |
Page 14 |
Page 15 |
Page 16 |
Page 17 |
Page 18 |
Page 19 |
Page 20 |
Page 21 |
Page 22 |
Page 23 |
Page 24 |
Page 25 |
Page 26 |
Page 27 |
Page 28 |
Page 29 |
Page 30 |
Page 31 |
Page 32 |
Page 33 |
Page 34 |
Page 35 |
Page 36 |
Page 37 |
Page 38 |
Page 39 |
Page 40 |
Page 41 |
Page 42 |
Page 43 |
Page 44 |
Page 45 |
Page 46 |
Page 47 |
Page 48 |
Page 49 |
Page 50 |
Page 51 |
Page 52 |
Page 53 |
Page 54 |
Page 55 |
Page 56 |
Page 57 |
Page 58 |
Page 59 |
Page 60 |
Page 61 |
Page 62 |
Page 63 |
Page 64 |
Page 65 |
Page 66 |
Page 67 |
Page 68