Abstract
Light extinction based optical wear particle counters (OPCs) have been widely used in the industry for oil condition monitoring for several years, and while experiments have tested the benefits and drawbacks of the measurement principle, limited research has been conducted regarding a theoretical approach to evaluate opportunities and limitations of the measurement scheme. In this paper, we present a method for theoretically modelling the output of an OPC based on the light extinction principle in the regime of geometrical optics, with a special focus on the influence of sensor optical design, particle concentration and measurement noise. Moreover, we show that, if only signal amplitude is considered, an algorithm for evaluating sensor output can cause an erroneous assessment of particle contamination level.
Highlights
Oil condition monitoring of operating machinery has over the last several years proven as an effective way of predicting imminent machinery breakdown
We present a method for theoretically modelling the output of an optical wear particle counters (OPCs) based on the light extinction principle in the regime of geometrical optics, with a special focus on the influence of sensor optical design, particle concentration and measurement noise
The working principle of a typical OPC based on light extinction is shown in Figure 1, where it is illustrated how a particle present in the sampling volume causes a shadow to be projected onto the detector located opposite to the light source
Summary
Oil condition monitoring of operating machinery has over the last several years proven as an effective way of predicting imminent machinery breakdown. Common features of OPCs, currently available for oil condition monitoring, are a lower particle size standardised detection limit of 4 μm, as stated by manufacturers, and the use of an empirical calibration technique according to ISO 11171:2016 [9]. OPC, while Section 3 states the theoretical investigation on the influence of the optical design on the output signal of an OPC, when assuming spherical particles and a perfect collimated light source These findings are utilized to develop the simulation tool and the simple particle detection algorithm, introduced in Sections 4 and 5, respectively.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
