Automatic oxidation stability testerBy simulating a high-temperature and high-pressure oxidation environment, the antioxidant capacity of substances can be quantified using pressure changes or oxygen bomb methods. Core working principle:

　　Automatic oxidation stability testerBy controlling key parameters such as temperature and oxygen concentration, the oxidation cycle of the sample is shortened, and the characteristic changes in the oxidation reaction are captured in real time by sensors, and then quantified results are output through data processing. The specific process can be divided into three steps:

Sample pretreatment and environmental control

Load the test sample into a dedicated reaction container and place the container in the instrument's constant temperature reaction chamber. The instrument stabilizes the temperature at the set value through a high-precision temperature control module, while introducing a stable flow rate of oxygen (or air) into the reaction chamber to simulate the oxidation environment of the sample during storage and transportation.

Dynamic monitoring of oxidation process

Oxidation reactions can cause changes in the physical and chemical properties of samples. Instruments monitor these changes in real time through specific sensors, and different detection principles correspond to different monitoring methods. Mainstream technologies include:

Pressure sensing method: In the oxidation reaction, the sample consumes oxygen to generate oxides such as carbon dioxide and aldehydes and ketones. In a sealed reaction system, oxygen consumption can cause a decrease in cabin pressure. The instrument records the pressure change curve over time through a high-precision pressure sensor. When the pressure drops to a set threshold, the corresponding time is called the "oxidation induction period (IP)". The longer the induction period, the stronger the oxidation stability of the sample.

Conductivity/Resistance Method: Some samples will generate polar substances after oxidation, leading to an increase in their conductivity. The instrument monitors the conductivity changes in real time by inserting electrodes into the sample, and the time of sudden conductivity changes is the oxidation induction period.

Differential Scanning Calorimetry (DSC): Oxidation reactions are mostly exothermic reactions. The DSC module monitors the temperature difference between the sample and the reference material (inert substance), records the oxidation exothermic curve, and the time when the exothermic peak appears is the induction period. At the same time, the exothermic amount can be quantified to reflect the severity of the oxidation reaction.

Data processing and result output

The built-in data acquisition and analysis system of the instrument will automatically record the monitored pressure, conductivity, temperature difference and other data, generate time parameter change curves, and calculate key indicators such as oxidation induction period (IP) and oxidation rate constant through algorithms. Then output the results in the form of numerical and curve reports, with some models supporting data export for subsequent analysis and archiving.