Lovibond Silicone Oil can be used with all turbidity meters. It has the same refractive index as the sample cell glass. Sample cells and caps must be extremely clean and free from significant scratches. Apply a thin coating of silicone oil on the outside of the sample cells to mask minor imperfections and scratches that may contribute to light scattering.
1. Clean the inside and outside of the cells and caps by washing with a laboratory glass cleaning detergent. Follow with multiple rinses with distilled or demineralized water
2. Apply a small bead of silicone oil from the top to the bottom of the cell.
3. Use a Kim Wipe or equivalent soft oiling cloth to spread the oil uniformly over the outside of the sample vial. Wipe off the excess so that only a thin coat of oil is left. Make sure that the sample cell is almost dry with little or no visible oil.