A sensor configured to determine information related to one or more gaseous analytes in a body of fluid, the sensor comprising: an emitter configured to emit electromagnetic radiation such that the intensity of the emitted electromagnetic radiation oscillates in a periodic manner; a luminescable medium in operative communication with the body of fluid and arranged to receive electromagnetic radiation from the emitter, wherein the luminescable medium emits luminescent radiation in response to the electromagnetic radiation received from the emitter; a radiation sensor arranged to receive the luminescent radiation, the radiation sensor generating an output signal that conveys information related to an intensity of the received luminescent radiation; and a processor configured to: sample the output signal generated by the radiation sensor at two or more predetermined periodic points over the oscillation of the intensity of the electromagnetic radiation emitted by the emitter; determine, based on the samples of the output signal, a DC level present in the output signal generated by the radiation sensor; and determine information, based on the samples of the output signal, related to a phase difference between the oscillation of the intensity of the electromagnetic radiation emitted by the emitter and oscillation of the intensity of the luminescent radiation received by the radiation sensor, wherein a manner in which the samples of the output signal are implemented in the determination of the information related to the phase difference is based on the determined DC level present in the output signal and is adjusted to account for the DC level. an emitter configured to emit electromagnetic radiation such that the intensity of the emitted electromagnetic radiation oscillates in a periodic manner; a luminescable medium in operative communication with the body of fluid and arranged to receive electromagnetic radiation from the emitter, wherein the luminescable medium emits luminescent radiation in response to the electromagnetic radiation received from the emitter; a radiation sensor arranged to receive the luminescent radiation, the radiation sensor generating an output signal that conveys information related to an intensity of the received luminescent radiation; and a processor configured to: sample the output signal generated by the radiation sensor at two or more predetermined periodic points over the oscillation of the intensity of the electromagnetic radiation emitted by the emitter; determine, based on the samples of the output signal, a DC level present in the output signal generated by the radiation sensor; and determine information, based on the samples of the output signal, related to a phase difference between the oscillation of the intensity of the electromagnetic radiation emitted by the emitter and oscillation of the intensity of the luminescent radiation received by the radiation sensor, wherein a manner in which the samples of the output signal are implemented in the determination of the information related to the phase difference is based on the determined DC level present in the output signal and is adjusted to account for the DC level. sample the output signal generated by the radiation sensor at two or more predetermined periodic points over the oscillation of the intensity of the electromagnetic radiation emitted by the emitter; determine, based on the samples of the output signal, a DC level present in the output signal generated by the radiation sensor; and determine information, based on the samples of the output signal, related to a phase difference between the oscillation of the intensity of the electromagnetic radiation emitted by the emitter and oscillation of the intensity of the luminescent radiation received by the radiation sensor, wherein a manner in which the samples of the output signal are implemented in the determination of the information related to the phase difference is based on the determined DC level present in the output signal and is adjusted to account for the DC level.