Lubricating Oils Foaming Characteristics Tester

Lubricating Oils Foaming Characteristics Tester

Foaming in lubricating oils can impair fluid flow, reduce heat transfer, and degrade bearing performance. The Lubricating Oils Foaming Characteristics Tester from Changsha Friend Experimental Analysis Instrument Co., Ltd. evaluates foaming tendency and foam stability following standard procedures such as ASTM D892.

Oil samples are conditioned at 24 °C and 93.5 °C in a foaming cylinder while air is sparged at a defined rate (typically 10 mL/min). Foam volumes are measured at the end of the air injection period and after specified collapse intervals (e.g., 5 minutes). The tester’s dual-temperature bath and precise air metering ensure that both foam formation and collapse are reproducibly assessed.

Key features include a transparent Pyrex cylinder with graduation markings, electronic mass-flow controller for air, and dual-zone thermostatic baths. A data interface records foam heights and timestamps, enabling calculation of foaming indices critical to ISO viscosity grading.

This instrument is widely used in gear, turbine, and compressor lubricant testing, where foaming can lead to cavitation, bearing damage, and pump cavitation. Formulators adjust anti-foam additives based on test results, while QC labs screen each production lot.

Best practices involve degassing samples before testing, verifying bath temperatures with calibrated probes, and checking air flow calibration monthly. By routinely evaluating foaming characteristics, users can prevent equipment damage caused by persistent foam.