Particle sensor for detecting or analysing particles in a fluid, the particle sensor comprising: an emitter for emitting an electromagnetic wave, a modulator for modulating the electromagnetic wave, a detection space for containing the fluid; a detector comprising a reference fluid chamber and a reference pressure or temperature sensor, wherein the reference fluid chamber contains a reference fluid, and wherein the reference pressure or temperature sensor is arranged to sense a pressure or temperature wave of the reference fluid in the reference fluid chamber, a further detector comprising a further reference fluid chamber and a further reference pressure or temperature sensor, wherein the further reference fluid chamber contains a further reference fluid, wherein the further reference pressure or temperature sensor is arranged to sense a further pressure or temperature wave of the further reference fluid in the further reference fluid chamber, and a controller for detecting or analysing a chemical particle in the fluid based on the pressure or temperature wave sensed in the reference fluid chamber, wherein the controller is configured to correct the measurement of the particles in the fluid from an influence of intensity fluctuations of the electromagnetic wave based on the pressure or temperature wave sensed in the reference fluid chamber and on the further pressure or temperature wave sensed in the further reference fluid chamber wherein the emitter and the detector are arranged such that the emitted electromagnetic wave traverses the detection space, and such that at least a part of the electromagnetic wave which traversed the detection space enters the reference fluid chamber, wherein the emitter and the further detector are arranged such that the electromagnetic wave traverses the detection space, and such that at least a part of the electromagnetic wave which traversed the detection space enters the further reference fluid chamber, wherein the reference fluid in the reference fluid chamber comprises the chemical particle to be detected or comprises another chemical particle which has similar absorption characteristics for the electromagnetic wave as the chemical particle to be detected, characterized in that the further reference fluid in the further reference fluid chamber comprises a further chemical particle which does not appear in the fluid or which absorbs frequencies of the electromagnetic wave which are not absorbed in the fluid. an emitter for emitting an electromagnetic wave, a modulator for modulating the electromagnetic wave, a detection space for containing the fluid; a detector comprising a reference fluid chamber and a reference pressure or temperature sensor, wherein the reference fluid chamber contains a reference fluid, and wherein the reference pressure or temperature sensor is arranged to sense a pressure or temperature wave of the reference fluid in the reference fluid chamber, a further detector comprising a further reference fluid chamber and a further reference pressure or temperature sensor, wherein the further reference fluid chamber contains a further reference fluid, wherein the further reference pressure or temperature sensor is arranged to sense a further pressure or temperature wave of the further reference fluid in the further reference fluid chamber, and a controller for detecting or analysing a chemical particle in the fluid based on the pressure or temperature wave sensed in the reference fluid chamber, wherein the controller is configured to correct the measurement of the particles in the fluid from an influence of intensity fluctuations of the electromagnetic wave based on the pressure or temperature wave sensed in the reference fluid chamber and on the further pressure or temperature wave sensed in the further reference fluid chamber wherein the emitter and the detector are arranged such that the emitted electromagnetic wave traverses the detection space, and such that at least a part of the electromagnetic wave which traversed the detection space enters the reference fluid chamber, wherein the emitter and the further detector are arranged such that the electromagnetic wave traverses the detection space, and such that at least a part of the electromagnetic wave which traversed the detection space enters the further reference fluid chamber, wherein the reference fluid in the reference fluid chamber comprises the chemical particle to be detected or comprises another chemical particle which has similar absorption characteristics for the electromagnetic wave as the chemical particle to be detected, characterized in that the further reference fluid in the further reference fluid chamber comprises a further chemical particle which does not appear in the fluid or which absorbs frequencies of the electromagnetic wave which are not absorbed in the fluid.