Twelve centrifuge tubes were filled with 10 mL of one of the cleaning/contaminant solutions. The tubes were placed into a Fisher Centrific® Centrifuge, Model 225 and run for varying time periods and speeds settings. Table 1 lists the times and speeds used. After each time period, one tube was analyzed for %Transmittance using a LaMotte’s Smart Colorimeter at 605 nm.
Table 1. Centrifuge Operating Conditions
| Contaminant
|
Time
|
Speed
|
%T
|
| 1
|
0
|
0
|
58
|
| 1
|
5
|
1/4
|
68
|
| 1
|
5
|
1/2
|
72
|
| 1
|
5
|
3/4
|
74
|
| 1
|
10
|
3/4
|
75
|
| 1
|
30
|
3/4
|
79
|
| 2
|
0
|
0
|
72
|
| 2
|
30
|
3/4
|
85
|
SUBSTRATE MATERIAL: Liquid
CONTAMINANTS: Iron Oxide (buffing compound) 1-Coarse, 2-Fine
CONTAMINATING PROCESS USED: Received contaminated
CLEANING METHOD: Centrifuge separation of Fe2O3 from cleaning solution.