In the process of preparation, reasonable selection should be made from reality to meet the requirements of frost resistance and economy. In the south of China, the proportion of ethylene glycol is generally 40%, while in the cold north, it is more appropriate to take the proportion of ethylene glycol with a mass fraction of about 50%.
PAL-9 1S and PAL-92S miniature digital ethylene glycol refractometers are specially used to measure ethylene glycol solution and display its solution concentration and freezing temperature. It has the advantages of simple operation, fast display speed and stable repeatability, which can better help our users to measure frozen liquid (name: antifreeze refractometer) and ensure the normal operation and service life of automobiles.
Ethylene glycol concentration (V/V): 0.0 ~ 90.0%, resolution: 0.2; Freezing temperature: 0 ~-50℃, resolution: 1℃ Measuring range: antifreeze concentration 0 to 70.0% Dissolution value 0. 1%.
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First, the function of adding defoamer to antifreeze: Because the automobile engine will inevitably vibrate during operation, air will enter the antifreeze to produce certain foam. This will affect heat transfer. However, adding an appropriate amount of defoamer into antifreeze can play a defoaming role when the concentration of defoamer reaches a certain level.
Defoamers mainly use alkyl nonionic surfactants, and generally useful ones are dehydrated glycerol ether, alcohol, silicone and so on.
Second, the role of adding non-toxic water-soluble colorant in antifreeze: Add non-toxic water-soluble colorant, and the (mass) concentration of colorant is generally in the range of 0.0 1% ~ 0.05%. The difference with cooling water is to check whether the antifreeze in the cooling system leaks, and at the same time, it has the function of reagent, which is convenient for observing the change of pH value of antifreeze.
Generally, methyl red, phenol red and methyl blue are commonly used to make the anti-migration agent have a certain indication function. If the observed color does not match the indicated color, it means that the antifreeze has been acidic, and the acidity will not play the role of antifreeze and rust prevention.
Third, the function of adding sterilization and mildew inhibitor to antifreeze: Because antifreeze is easy to produce microorganisms during storage, a small amount of sterilization and mildew inhibitor needs to be added in order to inhibit the growth of microorganisms and prevent antifreeze from moldy deterioration as much as possible, so as to ensure that antifreeze will not be moldy during storage for 2-3 years. Among them, sodium benzoate is better.
Fourthly, the function of adding corrosion inhibitor to antifreeze: Because the ph value of antifreeze will decrease and the medium will turn sour, adding corrosion inhibitor can control the PH value within a certain range. Commonly used PH regulators include organic amines, phosphates and phosphates.
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