Reserve Alkalinity of Engine Coolants

Description

Determines the ability of antifreeze to resist acidification during operation, indicating the residual life of anti-corrosion additives.

Reserve alkalinity is the chemical «shield» of your cooling system. During prolonged engine operation at high temperatures, the glycol base of the antifreeze inevitably degrades, forming aggressive organic acids (glycolic, formic, acetic). These acids can quickly destroy aluminum radiators and copper heat exchangers. Reserve alkalinity analysis at the RENA laboratory will show how much «vitality» is left in your coolant to neutralize these threats. This is a predictive maintenance tool that saves equipment from sudden corrosion. The test is performed by potentiometric titration (ASTM D1121) using an ultra-precise automatic titrator. An exact volume of the antifreeze sample (usually 10 ml) is dissolved in 90 ml of distilled water. A calibrated glass pH electrode is immersed in the solution, and the instrument begins to add the titrant in micro-doses — a standardized solution of hydrochloric acid (0.100 N HCl). The microprocessor continuously measures the change in the solution's pH. The volume of acid in milliliters consumed to drop the pH level to the critical mark of 5.5 is called the reserve alkalinity. The more milliliters consumed, the stronger the fluid's buffer.