Photo

 acid-base-number

Test equipment

Mettler Toledo T70 with automated sampler

LabX software

Sample size

50ml (recommended), 20-30ml (minimum)

Standard

ASTM D664

Unit

mgKOH/g

Test methodology

AN is determined by the amount of potassium hydroxide (KOH) base required to neutralize the acid in one gram of an oil sample. 

It is the measure of acidic concentration in the oil, detecting both weak organic acids and strong inorganic acids.

Notes (application)

A change in the acid concentration of an oil can originate from various sources. Acidic contaminants, wrong oil, alkaline-reserve depletion and oxidation by-products can cause an increase in acid concentration.

By comparing the fresh/reference oil values and trending the AN values, we can know if an oil is degraded or contaminated, and if it needs to be changed/recharged.

Suitable for systems

Any industrial lubricating oil used in hydraulic-systems, gearboxes, turbines, heat transfer systems, circulating-oil systems