The left-hand knob should be turned clockwise. Allow 10 minutes for warming up. Set the wavelength to the desired value using the knob on the top. T. Use the mirror behind the needle to avoid parallax error. Use the arrow button below the image to view more about parallax error.
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Wipe the cuvette with a dry Kimwipe to remove drops of solution or finger prints. Line up the mark on the cuvette with the line on the sample compartment. Insert cuvette filled with solvent in the sample compartment. Close the cover. To analyze your sample, insert sample cuvette and read the Absorbance value on the scale.