Hella 8PE 185 103-261 Mode D'emploi page 6

The threefold refractometer is proven and tested workshop equipment, which can be used to determine
whether coolant and/or windscreen washing water (centre and right scale) contains a suffi ciently high
amount of antifreeze. In addition, the left scale can be used to assess the AdBlue (urea/DEF) condition.
The light-dark cut-off line indicates on the scales up to which temperature in °C the liquid is protected
against freezing. The coolant scale is divided in:
a) ETHYLENE (is mainly used as antifreeze in Europe)
b) PROPYLENE (is mainly used as antifreeze outside Europe)
Long storage times and the impact of high temperatures cause a slow decomposition of AdBlue (urea-water
solution). Reference line (32.5 %) and the light-dark cut-off line should approx. match when checking
AdBlue. A shift of the light-dark cut-off line towards the waterline (5) indicates AdBlue decomposition.
The refractometer is fi tted with an adjustable eyepiece with which the device can be adjusted to the visual
acuity of the respective user.
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Test procedure:
• Check that prism (2) and cover (1) on the measuring device are clean.
• Use the enclosed pipette (6) to apply on drop of the liquid to be tested on the prism (2).
• Close cover (1) to distribute the drop.
• Turn eyepiece (3) to adjust to visual acuity.
• Read value on the respective scale. A clear light-dark cut-off line (4) appears.
• Clean/dry prism (2) and cover (1) using a clean, lint-free cloth after test completion.
Remarks:
The result of the windscreen washing water test is a mean value of alcohol-based antifreeze agents, as the
liquids have different compositions.
If the length of the pipette is not suffi cient to withdraw liquid, a clean plastic hose can be used alternatively.
To verify the indication accuracy of the device, use distilled water at 20 °C ambient/liquid temperature. The
light-dark cut-off line should match the waterline during the verifi cation. In case of deviations please contact
your dealer.