Table 3.

Coefficients for determinants of drift from axial fan airblast spray trials^a.

Fixed effects	Model estimate (95% CI)	SE	P-value
Intercept	3.17 (2.48, 3.87)	0.36	<0.001
Distance (m)	−0.05 (−0.06, −0.04)	0.01	<0.001
Height (m)	0.16 (0.11, 0.20)	0.23	<0.001
Wind speed (m/s)	0.53 (0.35, 0.70)	0.09	<0.001
Variance componentsb	Random and fixed effects included	Only random effect included
Within-location (Residual)	0.378 (80.2%)	0.499 (29.3%)
Between-location (Intercept)	0.093 (19.8%)	1.206 (70.7%)
Total variance	0.471 (100%)	1.705 (100%)

^aThere were 266 tracer-based drift volume levels (ln-µL) measured on polyester lines at 15 downwind locations in six spray trials.

^bWhen the fixed effects were dropped from the model, within-location variance was 0.499 (29.3%) and between-location variance was 1.206 (70.7%). Fixed effects impacted the between-location component of the variance (1.206–0.093; 92% reduction) considerably, but did not alter the within-location component of variance (0.499–0.378; 24% reduction) as much. The difference between these models suggests that there were relatively few systematic changes for individual locations across spray trials.