Checking The Antifreeze Content Using A Refractometer
Information
- The following diagram shows the scale used by Leitenberger
- The scales can vary, depending on the manufacturer, observe the operating instructions
- Use the "ETHYLENE" scale for Porsche coolant.
- The correct antifreeze content is given on the ETHYLENE scale
Position Designation Explanation -A- Scale for propylene-based coolant Do not use the scale for engine types M96/03, M96/05 and M97/01 -B- Scale for ethylene-based coolant Use scale for 997 engines -C- Scale for battery acid The charge state of a battery can be checked here. The figures indicate the gravity of electrolyte.
The battery must be recharged once the charge drops below 1.20.-D- Scale for alcohol-based windscreen cleaner The freezing point of the windscreen cleaner can be read off here. -E- Light/dark limit In conjunction with the points of intersection of the relevant scales, it specifies the value to be established -F- Waterline The light/dark limit must be located here when sprinkled with distilled water - Using a pipette, take a sample from the coolant expansion tank. Trickle a few drops onto the test surface of the refractometer.
- Close the light-diffusing lens. A closed liquid film must form.
Information
- The following table specifies how much coolant must be replaced by pure coolant in order to adjust the freezing point to -37 °C.
- Hold the refractometer against a bright light source. A clear light/dark limit emerges. The point of intersection between this line and the display scale marks the freezing point of the coolant. A freezing point that is too low must be adjusted according to the table below
Measured antifreeze content in °C Pure antifreeze quantity to be added (in liters) - 5 9 - 10 8.5 - 15 7.5 - 20 7.0 - 25 5.0 - 30 3.5 - 35 1.5