Calibration of Laser Fluorescence Measurements of Lubricant Film Thickness in Engines

David P. Hoult; Jeffrey P. Lux; Victor W. Wong; Stephan A. Billian

doi:10.4271/881587

1988-10-01

Calibration of Laser Fluorescence Measurements of Lubricant Film Thickness in Engines 881587

A laser fluorescent diagnostic method was employed to measure lubricant film thickness on the cylinder wall/piston interface of two engines. The system output signal was calibrated using lubricant samples of known thickness, and by comparison of a known piston ring profile to measured lubricant film contours. Agreement of the results of the two calibration methods was within 5%. A relative calibration was performed with three oils having different additive packages, and with an oil contaminated through use in a commercially operated engine. The calibration coefficients for the oils, relating output voltage to film thickness, varied within a factor up to two, depending on lubricant type and age.

The laser fluorescent apparatus was installed for use with a single cylinder test version of the Cummins VT-903 diesel engine. An optical passage was created through the block and cylinder wall using a quartz window. Preliminary results in the motored engine indicate a lubricant film thickness of approximately two microns, at the upper portion of the cylinder wall, on the minor-thrust face.

SAE MOBILUS

Subscribers can view annotate, and download all of SAE's content. Learn More »

Access SAE MOBILUS »

Digital $37.00 Print $37.00

Preview Document

We also recommend:

Standards

SAE Mobilus®

Publications

News

Events

Professional Development

A World in Motion (PreK-12)

Participate with SAE

SAE Membership

Donate

Calibration of Laser Fluorescence Measurements of Lubricant Film Thickness in Engines 881587

SAE MOBILUS