Measuring devices are usually set or calibrated at a temperature of
20°C. Liquids expand as the temperature increases, thereby changing the density to be measured. The flotation scale in our glycomat (for MEG + MPG) compensates for these effects within the normal range by its own expansion.
Glass areometers cannot expand, and only produce accurate measurements at 20°C. Corresponding value correction tables can be used for the different media to be measured. Our coldomat anti-freeze tester has an integrated thermometer and a value table for MEG. The gefo s/th acidity tester has a built-in thermometer.

Anti-freeze agents for cooling circuits

Coolant additives plus water produce the anti-freeze agent which is filled into the radiator. The coolant additive is a corrosion/anti-freeze agent (concentrate), which contains corrosion inhibitors (approx. 5%), anti-freeze agents (approx. 93%, MEG or MPG) and water. Such agents include:

Monoethylene glycol (MEG)
Synonyms: Ethylene glycol, MEG, monoethylene glycol, ethylene glycol, ethandiol

MEG is generally used for vehicle cooling systems.

The freezing point of this anti-freeze agent falls, depending on the manufacturer, from approx. -10°C to -40 °C with a water proportion of approx. 20 to 50 Vol% and then rises again on further concentration. At maximum concentration, the freezing point is approx. -13°C!

and

Monopropylene glycol
Synonyms: Propylene glycol, MPG, propandiol

MPG is used in the area of solar systems, heat pumps, in the foodstuffs industry and pharmaceuticals.
The freezing point falls continuously to approx. -59°C at maximum concentration.

Anti-freeze agents for the windscreen washer system

High-quality anti-freeze agents primarily provide cleaning performance, then anti-freeze protection, material compatibility and minimum stress on people and the environment.

The windscreen washer fluid (concentrate) consists of ethanol (approx. 79%) and monoethylene glycol (approx. 8%) for anti-freeze protection and to prevent rapid icing or icing of the nozzles. It also contains anionic and non-ionic tensides for cleaning, the removal of insects and salt in winter. The remainder consists of dyes, scents and water.

The ideal mixing ratio is approx. 30 Vol% windscreen washer fluid and 70 Vol% water, which ensures anti-freeze protection down to approx. -18°C.
If the concentration is increased, this increases the stress on paintwork, front and rear lights, SRF pipes etc. A sufficient amount of water is also required in order to clear the dirt released by the tensides from the windscreen.

Next to the electrical system, the cooling system in the car is most susceptible to problems.

Anti-freeze agents with their corrosion inhibitors reliably protect all metals found in the cooling system against corrosion and deposits. This increases the functional reliability and the service life of the cooling system components such as the radiator, heat-exchanger, water pump, cylinder head and engine.

Aluminium engines place higher requirements on corrosion protection. All automotive manufacturers research continually and intensively into further development, in co-operation with the manufacturers of anti-freeze agents. The approval conditions of the automotive manufacturers for common anti-freeze agents must also be observed.

Yes! Concentrated MEG freezes at approx. -13°C, and should not be stored at lower temperatures. Concentrated MPG only freezes at approx. -59°C, and in most regions can be stored in the open without any problem.

Coolants age differently, depending on the stress, and regular replacement is therefore necessary for safety purposes. Anti-freeze protection is primarily corrosion protection, so that coolant is used worldwide and is an all-year-round subject from the point of view of maintenance. When replacing metal components in the cooling circuit, the new components have many reactive surfaces. In order to provide these with a sufficient quantity of organic or inorganic corrosion protection inhibitors, regular replacement of the coolant is also advisable for this reason.

When water freezes, it increases in volume (at 0°C by approx. 9%).
Cooling circuits cannot withstand this pressure, and can be severely damaged.
Depending on their concentration, anti-freeze agents can reduce the freezing point to -40°C and below, thus offering adequate protection against damage.

The boiling point of anti-freeze/water mixtures is increased to approx. 110°C, and therefore also offers protection against overheating of the cooling circuit.

Measuring devices are usually set or calibrated at a temperature of
20°C. Liquids expand as the temperature increases, thereby changing the density to be measured. The flotation scale in our glycomat (for MEG + MPG) compensates for these effects within the normal range by its own expansion.
Glass areometers cannot expand, and only produce accurate measurements at 20°C. Corresponding value correction tables can be used for the different media to be measured. Our coldomat anti-freeze tester has an integrated thermometer and a value table for MEG. The gefo s/th acidity tester has a built-in thermometer.

Measuring devices are usually set or calibrated at a temperature of
20°C. Liquids expand as the temperature increases, thereby changing the density to be measured. The flotation scale in our glycomat (for MEG + MPG) compensates for these effects within the normal range by its own expansion.
Glass areometers cannot expand, and only produce accurate measurements at 20°C. Corresponding value correction tables can be used for the different media to be measured. Our coldomat anti-freeze tester has an integrated thermometer and a value table for MEG. The gefo s/th acidity tester has a built-in thermometer.