A method for detecting a particle in a fluid flow, said method comprising the steps of: providing said fluid flow having said particle, said flow having a flow direction; exposing said fluid flow to a beam of electromagnetic radiation (110, 615), wherein interaction between said particle and said beam of electromagnetic radiation (110, 615) generates scattered electromagnetic radiation from said particle; directing at least a portion of said scattered electromagnetic radiation from said particle onto a plurality of detector elements provided in an array of a two-dimensional detector; detecting at least a portion of said scattered electromagnetic radiation directed onto said plurality of detector elements, wherein at least a portion of said detector elements of said array generate output signals corresponding to intensities of said scattered electromagnetic radiation from said particle; measuring output signals for at least a portion of said detector elements of said array; identifying a particle detection signature (505, 510, 515, 520, 525, 530) for said particle, wherein said particle detection signature (505, 510, 515, 520, 525, 530) is a pattern comprising a plurality of output signals of detector elements each having an output signal greater than or equal to a threshold value for a given detector element; wherein the threshold value for the given detector element of said particle detection signature is greater than or equal to 2.5 times a standard deviation of noise for that detector element, wherein said pattern of output signals of said particle detection signature (505, 510, 515, 520, 525, 530) comprises a longitudinal component corresponding to a distribution of intensities of said scattered electromagnetic radiation along said flow direction; said longitudinal component comprising output signals from between 2 and 20 directly neighboring detector elements provided along a longitudinal axis corresponding to said flow direction; and thereby detecting said particle in said fluid flow. providing said fluid flow having said particle, said flow having a flow direction; exposing said fluid flow to a beam of electromagnetic radiation (110, 615), wherein interaction between said particle and said beam of electromagnetic radiation (110, 615) generates scattered electromagnetic radiation from said particle; directing at least a portion of said scattered electromagnetic radiation from said particle onto a plurality of detector elements provided in an array of a two-dimensional detector; detecting at least a portion of said scattered electromagnetic radiation directed onto said plurality of detector elements, wherein at least a portion of said detector elements of said array generate output signals corresponding to intensities of said scattered electromagnetic radiation from said particle; measuring output signals for at least a portion of said detector elements of said array; identifying a particle detection signature (505, 510, 515, 520, 525, 530) for said particle, wherein said particle detection signature (505, 510, 515, 520, 525, 530) is a pattern comprising a plurality of output signals of detector elements each having an output signal greater than or equal to a threshold value for a given detector element; wherein the threshold value for the given detector element of said particle detection signature is greater than or equal to 2.5 times a standard deviation of noise for that detector element, wherein said pattern of output signals of said particle detection signature (505, 510, 515, 520, 525, 530) comprises a longitudinal component corresponding to a distribution of intensities of said scattered electromagnetic radiation along said flow direction; said longitudinal component comprising output signals from between 2 and 20 directly neighboring detector elements provided along a longitudinal axis corresponding to said flow direction; and thereby detecting said particle in said fluid flow.