Device for measuring the quantity of solid particles in a gas medium

Device for detecting the amount or concentration of solid particles of nanometric or sub-micrometric size in a gas medium, in particular particulate matter in the exhaust gas of an internal combustion engine, comprising:

• a structure for the deposit of solid particles present in the gas medium,
• at least a first and a second electrode associated to said structure, and
• means for measuring an electric quantity between the first and second electrode,
• wherein a plurality of cavities is defined in said structure, which act as collectors of solid particles present in the gas medium, the structure being arranged so as to enable collection of said particles inside said cavities, and
• wherein a first end of said cavities overlooks said first electrode, which acts as a closing element for said cavities on said first ends.

Device for detecting the amount or concentration of solid particles of nanometric or sub-micrometric size in a gas medium, in particular particulate matter in the exhaust gas of an internal combustion engine, comprising:

• a structure for the deposit of solid particles present in the gas medium,
• at least a first and a second electrode associated to said structure, and
• means for measuring an electric quantity between the first and second electrode,
• wherein a plurality of cavities is defined in said structure, which act as collectors of solid particles present in the gas medium, the structure being arranged so as to enable collection of said particles inside said cavities, and
• wherein said measuring means are operative to detect a variation in the value of the measured quantity with respect to an initial or reference value, and to estimate in an integral way, as a function of said variation, the amount or concentration of solid particles in the gas medium.

Particulate matter sensor device for cumulative integral measuring of an amount or concentration of solid particles in a gas medium, the sensor device comprising:

• a structure for a deposit of submicrometric or nanometric solid particles of particulate matter present in the gas medium,
• at least a first and a second electrode associated to said structure, and
• means for measuring an electric quantity between the first and second electrode,
• wherein a plurality of cavities is defined in said structure, which act as collectors of said solid particles, the structure being arranged so as to enable collection of said solid particles inside said cavities, wherein
• said structure comprises a porous body made of an electrically insulating material, the porous body having through pores constituting at least part of said cavities, said pores having a first end and a second end,
• said porous body is arranged between said electrodes such that said first electrode closes said pores at the first ends thereof and said second electrode does not obstruct said pores at the second ends thereof,
• the sensor device is designed to be arranged within a conduit in which a flow of said gas medium flows in a flow direction, with the second ends of said pores being opposed to said flow direction such that said solid particles can enter said pores and progressively accumulate therein in presence of the flow of the gas,
• and wherein said measuring means are arranged for:
• measuring an initial value of said electrical quantity,
• detecting a variation of the electrical quantity with respect to said initial value, due to accumulation of said solid particles in said pores caused by said flow of the gas, and
• estimating in an integral way, as a function of said variation of the electrical quantity, the amount or concentration of said solid particles in the gas medium.