A method of recalibrating a device for assessing concentration of at least one analyte ion in a liquid, the device having: a plurality of ion selective electrodes, ISEs, each of which generate a signal in response to sensing a selected ion in the liquid; and a data processing unit implementing a neural network algorithm that has been trained to calculate ion interference between the selected ion and other ions in the liquid sensed at one of the electrodes and/or electrode interference between ones of the electrodes sensing a same selected ion based on a result of a comparison of training data indicative of known ionic concentrations applied to the neural network algorithm and the known ionic concentrations, the method includes: contacting, with the plurality of electrodes, more than one recalibrating sample having n selected calibration ions and a plurality of interference calibration ions of known ionic concentrations, respectively, whereby each of the n selected calibration ions correspond to ones of the plurality of electrodes; and the data processing unit: receiving a signal from each of the electrodes in response to sensing an ionic concentration of a corresponding one of the n selected calibration ions and the plurality of interference calibration ions in the more than one recalibrating sample; simulating a response of each of the plurality of electrodes by applying the signal as recalibration training data to a recalibration algorithm that has been trained to simulate the response based on a comparison of the recalibration training data and the known ionic concentration of the n selected calibration ions and the plurality of interference calibration ions, wherein simulating the response of each of the plurality of electrodes can be expressed as: V ISE = V pC Selected + ∑ i = 1 n Δ V pC Selected − pC Interferon i V ISE ≈ a × pC Selected + b + ∑ i = 1 n c i × e d i × pC Selected − pC Interferon i where: V ISE = the potential response value of the first ISE electrode in mV; VpC Selected = the potential value caused by the first selected calibration ion in mV; ΔV = the potential difference of each one of the plurality of electrodes ISE's response caused by each of the plurality of interference calibration ions in mV; pC Selected = the concentration of the first selected calibration ion in -lg M; pC Interferon i = the concentration of the i th one of the interference calibration ions in -lg M; and a, b, c i and d i = the parameters for the i th one of the interference calibration ions to be determined; and recalibrating the device by determining and optimising the parameters a, b, c i and d i based on the known ionic concentrations of the n selected calibration ions and the plurality of interference calibration ions in the more than one recalibration sample. contacting, with the plurality of electrodes, more than one recalibrating sample having n selected calibration ions and a plurality of interference calibration ions of known ionic concentrations, respectively, whereby each of the n selected calibration ions correspond to ones of the plurality of electrodes; and the data processing unit: receiving a signal from each of the electrodes in response to sensing an ionic concentration of a corresponding one of the n selected calibration ions and the plurality of interference calibration ions in the more than one recalibrating sample; simulating a response of each of the plurality of electrodes by applying the signal as recalibration training data to a recalibration algorithm that has been trained to simulate the response based on a comparison of the recalibration training data and the known ionic concentration of the n selected calibration ions and the plurality of interference calibration ions, wherein simulating the response of each of the plurality of electrodes can be expressed as: V ISE = V pC Selected + ∑ i = 1 n Δ V pC Selected − pC Interferon i V ISE ≈ a × pC Selected + b + ∑ i = 1 n c i × e d i × pC Selected − pC Interferon i where: V ISE = the potential response value of the first ISE electrode in mV; VpC Selected = the potential value caused by the first selected calibration ion in mV; ΔV = the potential difference of each one of the plurality of electrodes ISE's response caused by each of the plurality of interference calibration ions in mV; pC Selected = the concentration of the first selected calibration ion in -lg M; pC Interferon i = the concentration of the i th one of the interference calibration ions in -lg M; and a, b, c i and d i = the parameters for the i th one of the interference calibration ions to be determined; and V ISE = the potential response value of the first ISE electrode in mV; VpC Selected = the potential value caused by the first selected calibration ion in mV; ΔV = the potential difference of each one of the plurality of electrodes ISE's response caused by each of the plurality of interference calibration ions in mV; pC Selected = the concentration of the first selected calibration ion in -lg M; pC Interferon i = the concentration of the i th one of the interference calibration ions in -lg M; and a, b, c i and d i = the parameters for the i th one of the interference calibration ions to be determined; and recalibrating the device by determining and optimising the parameters a, b, c i and d i based on the known ionic concentrations of the n selected calibration ions and the plurality of interference calibration ions in the more than one recalibration sample.