Table 3.
Calculated effects and standard errors for the 23 factorial design.
| Effect | Factors | CoF | Pin wear (mg) | Disc wear (mg) | Particle number rate (104#/m) | Particle mass rate (μg/m) |
|---|---|---|---|---|---|---|
| Estimate ± standard error | ||||||
| Average | 0.55 ± 0.01 | 90 ± 9 | 53 ± 6 | 14 ± 4 | 0.64 ± 0.13 | |
| Main effects | Material (M) | −0.02 ± 0.02 | (42 ± 18) | 16 ± 12 | −12 ± 8 | −0.34 ± 0.26 |
| Speed (S) | (−0.05 ± 0.02) | −21 ± 18 | (40 ± 12) | −12 ± 8 | −0.12 ± 0.26 | |
| Pressure (P) | (−0.06 ± 0.02) | (67 ± 18) | −13 ± 12 | −17 ± 8 | −0.23 ± 0.26 | |
| Two-factor interactions | M × S | 0.01 ± 0.02 | −11 ± 18 | 5 ± 12 | 15 ± 8 | (0.64 ± 0.26) |
| M × P | 0.001 ± 0.02 | 25 ± 18 | 18 ± 12 | 14 ± 8 | (0.62 ± 0.26) | |
| S × P | (0.04 ± 0.02) | −5 ± 18 | (31 ± 12) | 15 ± 8 | (0.72 ± 0.26) | |
| Three-factor interaction | M × S × P | 0.001 ± 0.02 | −11 ± 18 | 2 ± 12 | −14 ± 8 | −0.31 ± 0.26 |