Adjust refractometer for determining the AdBlue® concentration - AR14.40-P-2041-01GZB

WARNING: This page does not describe the selected car, but rather 33 other vehicles, including the 2016 Mercedes-Benz E63 S AMG, 2016 Mercedes-Benz E400, 2016 Mercedes-Benz E350, 2016 Mercedes-Benz E300, and 2016 Mercedes-Benz E250. However, it is still accessible from the selected car via links, so may be relevant.

ENGINE 642 with CODE (U42) BlueTEC diesel exhaust treatment (SCR)

ENGINE 642.886 in MODEL 463.306 /336 /346

On equipment with automatic temperature compensation (ATC), temperature variations from 5 to 30°C/41 to 86°F are compensated automatically.

It is recommended to adjust the refractometer (5) before every checking procedure.

BLUETEC measurement

Clean prism (1) and hinged lid (2) of the refractometer (5) using a soft lint-free cloth.
The prism surface should not be touched by hand.

Fig 1: Prism And Hinged Lid Of Refractometer
Courtesy of MERCEDES-BENZ USA
Place 1 to 2 drops of distilled water on the prism (1) and close the hinged lid (2) using gentle pressure.
Closing of the hinged lid (2) causes the water to be distributed evenly.
See through eyepiece (4) against a light background.
Bring scales into focus by turning the eyepiece (4).
If necessary, carefully turn the adjustment screw (3) with a screwdriver, so that the bright/dark boundary is aligned with the zero line (water line).
Carefully remove any water residues from the prism (1) and hinged lid (2).