The present disclosure relates to a method and apparatus for cleaning a 3D printed article, in particular a 3D printed heat exchanger. After 3D printing, an article may have internal passages formed from bonded powder and said passages may contain unbonded powder that needs to be removed before further use of/processing of the article. To remove this unbonded powder, the article is filled with a cleaning fluid and vibrated. The cleaning fluid is then pumped out of the article and past a sensor that generates a magnetic field. The sensor detects the presence of powder particles in the fluid by detecting a perturbation of the magnetic field caused by said particles. The fluid is then filtered and returned to a reservoir for use. The sensor may indicate the article is sufficiently clean when a detected concentration of particles in the fluid drops below a threshold.

A diagnostic module for diagnosing a particulate matter sensor in a vehicle includes a sensor mode selection module, a heater power detector, and a protection tube diagnostic module. The sensor mode selection module selects a regeneration mode for the particulate matter sensor from among a plurality of operation modes. The regeneration mode regenerates the particulate matter sensor. The heater power detector determines a voltage output based on a voltage applied to the particulate matter sensor. The voltage output corresponds to operation of the particulate matter sensor in the selected mode. The protection tube diagnostic module performs a diagnostic of the particulate matter sensor. The protection tube diagnostic module selectively diagnoses a fault in the particulate matter sensor based on the voltage output determined during the regeneration mode and a regeneration power threshold.

A sensor for detecting electrically conductive and/or polarizable particles, in particular for detecting soot particles, includes a substrate and at least two electrode layers, a first electrode layer and at least one second electrode layer, which is arranged between the substrate and the first electrode layer. At least one insulation layer is formed between the first electrode layer and the at least one second electrode layer and at least one opening is formed in both the first electrode layer and the at least one insulation layer. At least some sections of the opening in the first electrode layer and of the opening in the insulation layer are arranged one above the other, such that at least one passage is formed to the second electrode layer.

An apparatus comprising: a body having an aperture dimensioned to receive an air-borne particle of corresponding size; first and second electrodes positioned within the aperture between which a potential difference can be applied; and a measurement circuit configured to measure an electrical property between the first and second electrodes such that the presence of the air-borne particle within the aperture can be detected based on a change in the electrical property when the air-borne particle contacts both the first and second electrodes.

A particulate matter sensor detecting particulate matter in exhaust emissions is provided, which is resistant to having sensor surfaces buried by particulate matter residue. Detection electrodes are provided, with alternating polarity, laminated in a laminating direction, separated by insulation. Of the detection electrodes, first detection electrodes of one polarity and second detection electrodes of the other polarity are exposed perpendicular to the laminating direction. In the direction perpendicular to the laminating direction, the particulate matter sensor has target accumulating parts on which the particulate matter is accumulated. In the target accumulating parts, the thickness W1 of the first detection electrodes in the laminating direction is greater than the thickness W2 of the second detection electrodes in the laminating direction.

Particle measurement apparatus comprises an inlet for receiving a gas sample for analysis, a photoionisation chamber, at least one light source arranged to illuminate an interior of the photoionisation chamber, first and second electrodes coupled to a power source and configured to provide a DC potential difference across at least a portion of the photoionisation chamber, and an outlet, together defining a gas flow path from the inlet, through the photoionisation chamber, and towards the outlet.

In a particulate detection system (10), a control board (911), a high voltage generation board (913) and an isolation transformer (720) are respectively disposed in a first space (921d) and a second space (921e) separated from each other by an inner case (923). When electromagnetic noise is generated in the high voltage generation board (913) and the isolation transformer (720); specifically, at the primary winding of the isolation transformer 720, at the time of switching the primary current supply, the electromagnetic noise is blocked by the inner case (923). This configuration reduces the influence of electromagnetic noise generated in the primary winding on the control board (911).

A particulate sensor can reduce the amount of floating ions discharged from the interior of a gas introduction pipe to the outside through a gas discharge opening, without providing an auxiliary electrode member which applies to the floating ions a repulsive force toward the gas introduction pipe to thereby assist the collection of the floating ions by the gas introduction pipe. The particulate sensor has an collection member which is connected to a gas introduction pipe to thereby be maintained at a collection potential and is disposed in the interior of the gas introduction pipe to be located between a forward end of the discharge electrode member and a gas discharge opening such that the forward end of the discharge electrode member cannot be visually recognized from the outside of the gas introduction pipe through the gas discharge opening.

Methods and systems are provided for a particulate matter sensor. In one example, the sensor may include a concave inlet for admitting exhaust gas from an exhaust passage downstream of a particulate filter into the sensor.

A detector includes a substrate including a first surface and a second surface opposite to the first surface, a funnel-shaped recess extending from the second surface of the substrate to the first surface of the substrate, a conductive layer disposed below the first surface of the substrate, an insulating layer disposed between the substrate and the conductive layer, and a first through via extending through the conductive layer and the insulating layer, and coupled to the funnel-shaped recess.