Acid number according to ASTM D974
AN-T-092
zh
绝缘油、变压器油和涡轮机油的酸值 (AN) 对于确保安全操作、运行设备控制和防腐蚀至关重要。这些油的 AN 值通常较低，通过手动显色滴定法测定 AN 值很困难，尤其是在分析有色样品时。这大大提高了结果的精确性和可靠性，从而改进了对操作的监控。
The acid number (AN) is an important indicator of the quality and safety of insulating, transformer, and turbine oils, which usually have low AN specifications. The manual color-indicator titration method recommended by ASTM D974 can be difficult to perform, especially for colored samples.
A better alternative is to use a titrator with a photometric sensor that can automatically detect the endpoint of the titration. This ensures consistent and reliable results, which can help to monitor and control operations more effectively.
This Application Note describes how to use the Optrode photometric sensor for the fully automated determination of the AN according to ASTM D974, ISO 6618, and IP 139. The sample is titrated with alcoholic KOH solution until the p-naphtholbenzein green-brown endpoint is reached. The endpoint is determined by a break point evaluation of the titration curve, which corresponds to the color change of the endpoint described in ASTM D974.