15. One cause of lumen degradation of metal halide are lamps is contamination inside of the are chamber and lamp jacket. A brainstorming session to address excessive lumen degradation identified four variables that might affect contamination. To test for variable effects a 2* full factorial experiment design with two replicates in blocks was built using the following variables matrix: Variable A: HF seld wash B1: Cadmium concentration || C: Vacuum exhaust time. D: Jacket getter + No Yes 24 Units NA % 30 60 seconds. 16 mm The experimental run matrix is shown below. The lumen maintenance response, LM, is the ratio of 1000 hour lumens to 100 hour lumens. (a) Analyse the data and refine the model. (b) Us the model to make a recommendation to improve lumen maintenance. Std Run Block | A BCD LM Std Run Block A BCD LM 10 1 0.948 27 17 2 -1 1 16 2 1 1 0.065 26 18 2 -1 1 1 0.935 1.008 3 T DIDIDI|-1 | 0.839 31 19 2 -I 13 4 1 -1 -1 1 0.855 29 20 2 1 1 П 1 -1 -1 1-10.855 21 21 2 -1 -1 1 -10,8 6 -1 -1 T | 0.901 22 22 2 -L 10.906 0.565 0.940 7 7 1 -1 1 -1 0.885 17 23 2 -1 -1 -1 -1 0.885 12 8 1 1 1 1 1 0.973 20 24 2 1 1 -1 -10.982|| 14 9 1 -1 1 0.941 19 25 2 -1 1 -1 -1 0.893 8 10 1 1 1 1 -1 0.950 28 26 2 1 1 -1 1 0.970 2 11 1 1 -1 -1 -1 0.928 2:3 27 2 -1 1 1 10,890 4 12 1 -1 -1 0.973 30 28 2 1 -1 1 0.949 15 13 -1 1 1 0.905 24 29 2 1 1 1 -1 0.967 3 14 1 1 1 -1 1 0.5537 18 30 2 1 -1 -1 -1 0.957 6 15 1 1 -1 1 -1 0.965 32 31 2 1 I 1 0.944 9 16 1 -1 -1 -1 1 0.833 25 32 2 -1 -1 -1 1 0.865

Fig: 1