Printed coil sensors for monitoring fluid condition
Various methods and systems for monitoring one or more characteristics of a fluid in a mechanical device are disclosed herein. In at least one embodiment, the system includes an optical sensor including an excitation light aperture and an emission light aperture. The excitation light aperture transmits an excitation light to the fluid and the emission light aperture receives an emission light from the fluid. The system may further include an inductive sensor including a printed circuit board including a first field coil trace, a second field coil trace, and a sense coil trace. The methods disclosed include transmitting the excitation light to the fluid; receiving the emission light from the fluid; and operating a processor to obtain one or more fluorescence spectra based on the received emission light; and determine a fluid condition indicator and/or a remaining useful life of the fluid based on the one or more fluorescence spectra.
1 . A system for monitoring one or more properties of a fluid in a mechanical device, the system comprising:
a printed circuit board (PCB)-based inductive sensor for detecting one or more metallic particles in the fluid, the PCB-based inductive sensor comprising:
a first PCB, a second PCB and a third PCB, the first PCB comprising a first field coil trace printed on one or more layers of the first PCB, the second PCB comprising a sense coil trace printed on one or more layers of the second PCB and the third PCB comprising a second field coil trace printed on one or more layers of the third PCB, and
a mesh structure, wherein the first PCB, the second PCB and the third PCB comprise one or more apertures, the one or more apertures being aligned and allowing the fluid to pass through, wherein the first field coil trace, the sense coil trace and the second field coil trace are wound around each aperture,
wherein the first field coil trace and the second field coil trace generate a magnetic field when electrically driven and the sense coil trace detects a change in the magnetic field produced by the one or more metallic particles in the fluid.
2 . The system of claim 1 , wherein the PCB-based inductive sensor further comprises at least one spacer component coupled to one or more of the first PCB, the second PCB and the third PCB, and wherein each spacer component is implemented in a substantially ring-shaped configuration with at least one aperture to allow the fluid to pass through.
3 . The system of claim 2 , further comprising an oil containment tube (OCT) for insertion into the corresponding one or more apertures to provide a sealed pathway for the fluid to pass through.
4 . The system of claim 3 , wherein each oil containment tube has a fluid conditioning curved opening.
5 . The system of claim 1 , wherein the PCB-based inductive sensor comprises a bypass channel formed in one or more of the first PCB, the second PCB and the third PCB to allow larger of the one or more metallic particles to pass through.
6 . The system of claim 1 , wherein the PCB-based inductive sensor further comprises a flow conditioner adjacent to one or more of the first PCB, the second PCB and the third PCB to guide the fluid to pass through the one or more apertures.
7 . The system of claim 1 , wherein the PCB-based inductive sensor comprises a plurality of coil triplets, each coil triplet comprising the first field coil trace of the first PCB, the sense coil trace of the second PCB and the second field coil trace of the third PCB, and wherein the plurality of coil triplets are coupled in a parallel configuration such that each coil triplet functions as an independent sensing element.
8 . The system of claim 1 , wherein the PCB-based inductive sensor comprises a plurality of first PCBs, a plurality of second PCBs and a plurality of third PCBs, and wherein the first field coil traces of the plurality of first PCBs are connected in series, the sense coil traces of the plurality of second PCBs are connected in series and the second field coil traces of the plurality of third PCBs are connected in series.
9 . The system of claim 1 , wherein the first field coil trace and the second field coil trace are configured to generate magnetic fields of opposite polarity, and wherein when the one or more metallic particles interact with the sense coil trace, a double-lobed voltage signal is generated.
10 . The system of claim 1 , wherein the PCB-based inductive sensor comprises one or more Faraday shield traces printed on one or more layers of at least one of the first PCB, the second PCB and the third PCB to attenuate electromagnetic interference.
11 . The system of claim 1 , wherein the fluid comprises a lubricant oil.
12 . The system of claim 1 , wherein the fluid comprises a fuel.
13 . The system of claim 1 , wherein the fluid comprises a transmission oil.
14 . The system of claim 1 , further comprising a probe, wherein the printed circuit board (PCB)-based inductive sensor is housed in the probe.
15 . The system of claim 14 , wherein at least a portion of the probe is insertable into the fluid.
16 . The system of claim 1 , wherein the PCB-based inductive sensor comprises a hydrodynamic profile to reduce pressure drop in the fluid flowing through the PCB-based inductive sensor.
17 . The system of claim 1 , wherein the PCB-based inductive sensor comprises one or more auxiliary sensors, the auxiliary sensors being hermetically sealed to one or more of the first PCB, the second PCB and the third PCB.
18 . The system of claim 1 , wherein the first PCB, the second PCB and the third PCB are fabricated from a chemically inert material configured to tolerate exposure to the fluid.
19 . The system of claim 1 , wherein the fluid comprises a hydraulic oil.