Method for automatically detecting acid value of synthetic lubricating oil

Abstract

A method for automatically detecting the acid value of synthetic lubricating oil comprises the following steps: adding a mixed solvent of an ester solvent and a hydrocarbon solvent and an indicator into a to-be-detected oil sample, and collecting the initial red color of liquid in a container through an RGB color collection sensor; dropwise adding a potassium hydroxide isopropanol standard titration solution; when the difference value between the initial color and the color collected in real time reaches 2 / 3 of a preset color threshold value, slowly dropwise adding a potassium hydroxide isopropanol standard titration solution; and when the color collected in real time reaches a preset color threshold value, stopping titration of the potassium hydroxide-isopropanol standard titration solution, and calculating the acid value of the to-be-detected oil sample according to the mass of the to-be-detected oil sample and the total dosage of the titrated potassium hydroxide-isopropanol standard titration solution. The to-be-detected synthetic oil is sequentially subjected to dissolution, room-temperature titration, automatic stopping and automatic result calculation to obtain the acid value of the to-be-detected synthetic oil sample, and the method has the characteristics of rapid titration process, simplicity in operation, economy, environmental protection and accurate result, and is worthy of popularization and application.

Description

technical field [0001] The invention belongs to the technical field of automatic detection of acid value of synthetic oil, and in particular relates to an automatic detection method of acid value of synthetic lubricating oil. Background technique [0002] Oil acid value test is usually potentiometric titration and color indicator method. The acid value test method using potentiometric titration requires the use of expensive precision instruments and electrodes, and the cost of the instruments is high. There are two acid value test methods using color indicators, one needs to use ethanol to heat and reflux, the test process has strict requirements on temperature, reflux and many other processes; the other needs to use the precursor chemical toluene, and the tested The recovery of waste liquid is difficult, the disposal cost is high, and the health of the test personnel is endangered during the test. The above two methods all have the problems of large oil volume, complicate...

AI Technical Summary

Problems solved by technology

In GB / T 4945, the color changes from orange to dark green during the acid value titration process. Therefore, in the detection process of synthetic oleic acid value, both red (R) and green (G) have obvious changes. If only green (G ) changes in the judgment of the end point, resulting in a large error in the test results of the synthetic oleic acid value

Images