Design of a fluorescent measurementsystem for compliant hydrostaticbearings

A LED induced fluorescent technique based test setup is introduced , which is used to measure the water film thickness of compliant hydrostatic bearings. Fluorescent particles have the characteristic of absorbing light of a certain wavelength and emitting light of a higher wavelength. A LED with a wavelength of 540 nm (green light) is used to excite the Rhodamine B fluorescent particles, which have a excitation wavelength of 545 nm. The emission wavelength of the particles is 570 nm (red light) and this colour shift is captured by a RGB colour camera where the red and green channels have been used as an optical filter. The increase of intensity due to the excitation of the thin film can be coupled to the thickness of the film. The performance of the technique is validated by comparing the film height to a laser sensor measured film height for a rigid bearing containing features with known dimensions. A film thickness measurement technique is presented that is able to measure 15-1400 $\mu$m and an average accuracy of 6.4\% is achieved.Mechanical Engineering | Mechatronic System Design (MSD