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Hi I am doing a Capstone Project at a company, we will just call it company X.
I have to find the best location to find the worst possible solution in a tank with acidic solution. I take samples and titrate them to find the acidity level and if solutions acidity drops, I can add more acid to strengthen the acidity to the required level. The goal is again to find the best location and volume to fins the worst sample. This will perform as an early detection system to keep the acidity to required strength.
The factors I have decided for this DOE are listed with their respective levels
1. Water type ( to rinse sample cup) water and RO water 2 levels
2. Time 6am when machine starts and 10 am 4hrs after the machine has started and the solution has been kept agitated 2 levels
3. Location front of tank and back of tank 2 levels
4. Size or volume 10ml 55ml and 100ml 3 levels
5. Depth of sample surface, 18 inches and bottom of tank 3 levels
By the hand work i figured the following for degrees of freedom for truth table
3 factors at 2 level = 3 * (21)= 3
2 factors at 3 level = 2 * (31)= 4
miu = 1
error = 1
DOF = 9
The problem with L9 table is that it does not incorporate level 3 settings
So i use Minitab to form a multi level taguchi design with 5 factors and L36 with 2**3 and 3**2 settings, i get a 36 experiment table, 12 of which are repeats so i am left with 24 experiments, the problem is when i perform the analysis the S/N ratio is wrong and way off compared to hand calculations. What am I doing wrong? Can some one please help. i can provide the data and the Minitab file. Thanks
Tina
EDIT: I have attached the files. the files were done in version 15 of minitab. also for analysis i was using larger the better option.
I have to find the best location to find the worst possible solution in a tank with acidic solution. I take samples and titrate them to find the acidity level and if solutions acidity drops, I can add more acid to strengthen the acidity to the required level. The goal is again to find the best location and volume to fins the worst sample. This will perform as an early detection system to keep the acidity to required strength.
The factors I have decided for this DOE are listed with their respective levels
1. Water type ( to rinse sample cup) water and RO water 2 levels
2. Time 6am when machine starts and 10 am 4hrs after the machine has started and the solution has been kept agitated 2 levels
3. Location front of tank and back of tank 2 levels
4. Size or volume 10ml 55ml and 100ml 3 levels
5. Depth of sample surface, 18 inches and bottom of tank 3 levels
By the hand work i figured the following for degrees of freedom for truth table
3 factors at 2 level = 3 * (21)= 3
2 factors at 3 level = 2 * (31)= 4
miu = 1
error = 1
DOF = 9
The problem with L9 table is that it does not incorporate level 3 settings
So i use Minitab to form a multi level taguchi design with 5 factors and L36 with 2**3 and 3**2 settings, i get a 36 experiment table, 12 of which are repeats so i am left with 24 experiments, the problem is when i perform the analysis the S/N ratio is wrong and way off compared to hand calculations. What am I doing wrong? Can some one please help. i can provide the data and the Minitab file. Thanks
Tina
EDIT: I have attached the files. the files were done in version 15 of minitab. also for analysis i was using larger the better option.
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