Device and method for monitoring the particle contamination in flowing hydraulic fluids
View Patent ↗A device for monitoring particle contamination in flowing hydraulic fluids includes a mechanism for particle counting and particle sizing. Further, a method for monitoring particle contamination in flowing hydraulic fluids: determines fluid flow velocity; counts particles in the hydraulic fluid passing the light barrier for a fixed period of time; and obtains particle size distribution by using a range of different trigger levels. The monitoring device is insertable into an A/C hydraulic system to enable an online-monitoring of degradation of fluid quality during normal flight operations or on the ground. The device and method help lower costs for A/C maintenance and increase A/C availability since necessary service actions can be scheduled strategically.
1. A device for monitoring particle contamination in flowing hydraulic fluids, comprising:
means for particle counting and particle sizing; and
two or more optical sensors having different light beam diameters.
2. A device for monitoring the particle contamination according to claim 1 , further comprising an optical sensor and a flow sensor.
3. A device for monitoring the particle contamination according to claim 2 , wherein the optical sensor is a photoelectric slot sensor.
4. A device for monitoring the particle contamination according to claim 3 , wherein the optical sensor has a light beam diameter of 100 μm.
5. A device for monitoring the particle contamination according to claim 2 , wherein the flow sensor is an ultrasonic transducer.
6. A method for monitoring particle contamination in flowing hydraulic fluids, the method comprising:
determining fluid flow velocity;
counting particles in hydraulic fluid passing a light barrier for a fixed period of time; and
obtaining particle size distribution by using a range of different trigger wherein the counting is performed using two or more optical sensors having different light beam diameters.
7. A method according to claim 6 , wherein repeated measurements of particle contamination are conducted to allow extrapolating the time at which a critical contamination level is likely to be reached.
8. A method according to claim 6 , wherein signal size and signal duration are attributed to particle size.
9. A method according to claim 6 , wherein a cumulative size spectrum and a differential size spectrum are used for calculating the particle size.
10. A method according to claim 6 , wherein a range of detectable particle diameters is pre-set to 10 μm to 100 μm.